Category: ArahPaint

Revisiting old color separations, testing present software methods

ArahPaint has become my most frequent go-to when designing repeats. A previous blog post explains the process used below.
More will be added as I review old posts.

From 2013 Block slip stitch separations
In developing DIY, beginning with symmetrical designs can lay the foundations for more varied pattern placements.
The re-drawn original 10X8 double length 10X16 two-row brush filled 12X16brush fill, white color to alpha added surrounding space, 16X21brick repeat offset by 11 rows, 48X42 isolating the repeat, BW indexed, 32X21 check tiling, 64X63 using a 2-row brush fill to visualize motif placements doubled in height for slip stitch knitting, 32X42 double height, color reversed, in repeat for knitting 64X84slightly different spacing, 28X20 double height, in repeat for knitting. 70X120Shapes on a nearly balanced ground require added steps
24X1124X22every-other row white color to alpha 24X22 drawn in repeat 48X6648X66 mirrored cropped to 24X66, using red for visibility copy and paste on the first BW repeat converting white color to alpha: begin in center continue with half repeats 48X66 3 color isolating the 24X22 repeatBW version checking tiling the color reversed PNGtested on 60 stitches, end needle selection on

Tips on Single bed tuck and slip stitch fabrics 2: adding color

Playing with diamond and argyle repeats

More than a decade ago, I began a library of Hound’s tooth FI variations
that grew over the years.
Recent questions on argyle patterning have led to this post, which will grow periodically.
Many of the related designs form floats wider than the recommended maximum of 5 stitches and will require some float control unless they are knit as DBJ.
Some repeats are also suitable for use with tuck or slip stitch settings.
Elongation in some knitting techniques is to be avoided if possible. In some of these instances, multiplying the height of the original repeat X2 produces the more visually familiar argyle shapes.
Repeat segments can be edited to develop custom variations
16X16tiled16X17 tiled 16X34 tiled 16X32tiled 16X20 tiled 16X4018X40
tiled 20X28 tiled 20X40tiled20X56 tiled24X24tiled   24X40tiled24X44
tiled24X48tiled24X48tiled24X48tiled24X48tiled24X48 tiled24X60 for border or horizontal bands of design trimmed to 24X52 for all-over patterning 24X96  tiled 32X44tiled 32X64tiled36X80tiled42X32tiled Passap 257 40X4040X80Working in multiple colors
36X3636X72 32X32
32X64A coloring book approach can be used to develop DIY designs by filling in segments in any repeats provided expanding the color palettes, or creating custom-sized diamond outlines and filling in individual shapes between lines with colors.
Beginning with a 24X48 design   visualization of patterns becomes easier on a larger canvas than one simply doubling the original to 48X4896X96the smallest repeat segment, 12X24 for quick color changes to custom A 24X48 repeat with all white outlines for filling in shapes reducing the number of colors shifting shapes: 12X48It is possible to form related shapes with hand-transferred stitches, as seen in Using punchcards to track small cables in pattern (1)

 

 

A DIY large scale repeat adapted from an online published collection

Electronic pattern books now available for free online often include images of mylars or of files for knitting using specific machine models and/or accessories.
The designs may be used as provided or serve as springboards for DIY variations.
Some knitters prefer large-scale designs in non-repetitive patterns on garment pieces.
Roses and houndstooth designs reappear frequently on runways. This was included in a Studio pub and caught my eye. Conversion to the full 96X172 file. Visualizing the potential large piece knit, it was not an instant favorite. Working towards a DIY design and examining varied methods and steps:
the inspired 4-stitch brush to be used in the background fills a small “rose” from a punchcard repeat, 24X24the first approach uses color to alpha to place the design on a pattern-filled ground, the file is adjusted to 30X30 to allow for outlining the rose in a third color the result, in turn, is centered on a 44X44 new image.
To have the white pixels forming the petals undisturbed when using color to alpha, the background is changed to cyan in a new window, fill a new picture, 44X44, with pattern copy and paste the flower, anchoring it in place after rendering the cyan transparent and change the magenta outline to white, tile to 132X132playing with the movement of the shapes to change the overall placement,  the brick repeat immediately shows patterning problems, and the shapes appear small the 30-pixel file is doubled in size to 60X60, check that the number of colors is set to 3, fill the white background with pattern magenta pixels to white the intersection problem in a standard brick repeat reoccurs if the white outline is considered too thick, reduce it to one pixel from 2.
In this 60X60 image, the lines forming the petals are also colored in magenta, and the outline is reduced from 2 pixels to 1, Changing the approach: the above is drawn in repeat on a white ground. Rotating any individual elements becomes possible with no disruption in the yet-to-be brush-filled design. Filling in the white ground with the pattern results in no tiling errors eliminating the third color, BW brick, it is not possible to isolate a smaller repeat keeping directions constant in alternate rows of the pattern makes isolating the smallest repeat possible, 60X120. Back to the inspiration florals, isolating one of the roses, 61X59, note that the shape is not symmetrical with a single-pixel third color outline, on a white ground, 64X64tiled in a simple brick repeat to 128X192 on a white ground with the background pattern-filled64X128 isolated smallest repeat tiled in BW with colored outline removed testing random placements produce a design with the smallest programmable repeat note that the horizontal distance between the flower shapes is not fixed

seeking symmetry 50X58 scaled to 58X58planning added borders 64X64  outlined a full single repeat 192X256 using the same random arrangement building the smallest straightforward single brick repeat if there are limitations on the size of the programmed image ie to avoid multiple tracks in machines such as the 930 using img2track the slightly scaled design reduced to an 80X80 repeat to play with in any configuration of your choice. The test swatch for the full single repeatContinuing on a floral theme, inspired by a filet crochet design, 30X90 its half drop version, 60X90drawing both in repeat to 180X180 helps to determine whether further editing is needed, and if the shift in vertical/horizontal vs diagonal striping is preferred  

DIY pattern design groups developed in 2 or more colors

Although knitting designs in more than 2 colors is associated with issues in maintaining aspect ratio and discussing the performance of specific color separations, PNGs planned in multiple colors can serve as a paint-by-numbers start and eventually be reduced to BW.
In DIY begin with a small repeat for pattern repeat and knitting tests to determine preferred techniques and final appearance
18X16the pattern movement determines the single repeat size
48X48Familiarity with software aids in developing baseline custom charts that are useful in planning DIY designs in linear, diagonal, or rotated aspects.
Chosen motifs can be added and distributed based on personal preferences.
The first charted grid for later motif placements begins here with a 40X40 repeat

also isolated to 80X80Working with seasonal motifs after removing a few more pixels 
creating  blank negative spaces or areas for other motif additions varying the frames for each segment,
32X32
with added blank rows 32X40adjusting foundation grid repeat, 52X52 a published repeat with source designs isolate and add motifs, erase or change pixel colors to suit, choose final segment(s) to place in the overall design  
color to alpha isolate the smallest repeat, 52X52 Working with horizontal repeats: the appearance at this scale of a third color is an illusion, the PNGs are BW
38X52 with half the height color reversed  adjusted to 36X50When intending to explore colorways matching available yarns in fair isle bands, work with expanded palettes/RGB mode a cousin in BW began with 36X126 steps in editing removing/adding a few more bothersome (to me) pixels Making choices to retain a specific shape, in this case, the star formed by adjoining blocks and triangles: the starting PNG, 36X36plotted on a 12X12 grid, drawn in repeat to 144X144 resized to 18X18in the tiled repeat, 144X144, the orange blocks remain 12X12, drawn here with a 6X6 grid developing tumbling blocks: a beginning outline, 28X28drawn in repeat to check overall alignment filling in with colors to form secondary shapes
..

 

Geometric shapes on ribber fabrics formed with tuck stitches 4

The term brioche in knitting is often used loosely in any references to tuck stitches. Here the term refers to vertical designs specifically produced with hand techniques, moving groups of stitches on the top bed.
Designs may be worked in single colors, or with more complicated planning, they may be executed in 2 colors.
For executing blocks of texture in one or two colors with and without racking  see Fisherman_ English tuck stitch rib 1_ checks patterns_ Brother, Passap 
racked, single-color sample. Other explorations of the use of tuck stitch settings in 2-color double-bed every needle rib fabric began with attempting to create a solid color shape on a vertically striped ground in Geometric shapes on ribber fabrics with tuck stitches 1  Another simple shape was programmed, and varied carriage settings on either or both beds were explored in Geometric shapes on ribber fabrics with tuck stitches 2; knitting with 4 carriages. Geometric shapes on ribber fabrics with tuck stitches 3  uses self-drawn repeats and  multiple colors. varying carriage settings while using only 2 colors  Lace transfers meet fisherman rib in 2 colors on Brother KM 1Lace transfers meet fisherman rib, 2 color ribbed brioche on Brother machines 2 , one of several swatches. These are advanced, complex fabrics. The repeats for 2 colors can grow exponentially in length.
Returning to designing suitable repeats, beginning in a spreadsheet: grey vertical lines represent stitches on the ribber, which will force apart stitches created on the top bed forming the more familiar tuck rib surface. Mac Numbers offers the opportunity to hide either/ both columns and rows. In this instance, with the 10 grey columns hidden, one begins to get the sense of shapes and movements needed on the top bed   Working toward a repeat for knitting the shapes in a single color, imagining the location of eyelets resulting from stitch transfers, I used two repeats, adjusting the first one to vary the resulting shape slightly A 11X30 repeat mirrored horizontally for use on my 930, tiled twice horizontally before programming and downloading, used as a 23X30 single motif to obtain a matching border on each side, A 9X28 repeat, my second try, programmed as a 20X28 single motif, As described in previous posts, in knitting using only one color, the machine is set with the main bed tucking on every needle in one direction, followed by knitting on every needle as it returns to the starting side, the ribber does the same but in the opposite direction. It is a circular tuck, also referred to as fisherman’s rib. A slight shift in patterning may change the outline of the desired shape, requiring introducing or removing stray lines or secondary shapes.
The cam setting options: In a two-color brioche, when no needles are selected on the top bed (white squares), the top bed will tuck every needle; the ribber is set to knit. 

When needles are selected on the top bed (black squares), the ribber is set to tuck in both directions. Brother preselects needles for the next row to be knit, on rows with partial selection and some needles in the B rather than the D position, with an appropriate transfer tool, move the stitches on the non-selected needles to the adjacent selected needles to their right after pushing it (them) back to the B position.
After each transfer, push all needles involved in the transfer and the now empty needle to the E position.
As the carriage returns to the opposite side an all-knit row will be completed. Several tension adjustments may be needed to ensure loops are not hung up on gate pegs as stitches move across the bed, while still being loose enough to knit off properly.
A first repeat, plotted in a spreadsheet including borders Here groups of columns are eliminated to bring the shapes close together The yarns used are white 2/15 and red 2/10 wool.  The latter is coarsely spun and tends to split and occasionally not properly knit off, resulting in the specks on the white columns on the reverse, making it a poor choice for final projects.

Studio/Silver Reed machines published some designs for pile knitting in their punchcard volume  

The inspiration page   The #14 24X42 repeat used in this sample was color-reversed before being downloaded to the 930  checking tiling punchcard machine users would punch all black cells. The pattern is worked with end needle selection canceled, the knit carriage is set to tuck in both directions and the ribber carriage to knit in both.
The first and last needles in work are on the ribber bed.

The #13 design, is composed of 24X16 segments  repeated X2
The 16X32 rendered double length to 24X32 was used to knit this slip-stitch double bed fabric  The 24X16, file color was reversed and this 26X32 file added black pixels in width for more definition of the shapes The yarn used is a 2/20 wool, so thin that there is less definition between the two stitch types and enough open space between the stitches to show the surface beneath the swatch, which measures 13.5 inches in width, 7.25 in height A DIY attempt at a large scale design: the 24X38 was found in Pinterest, published in 2018 and credited to a Russian site.
The starting design, in BW indexed mode 24X38 the tiled repeat results in a horizontal striping 24X38 scaled in Gimp X4 to 96X152 Mode >RGB
open a new file, in this case, 8X2 using a color and white
white color to alpha, copy to clipboard to use it as a brush
bucket fill the first image with the pattern click on the select by color tool, click on the red, and use the bucket fill tool again, making certain that the background or foreground colors are selected, not pattern fill  click on the rectangle select tool and back in the work window to fix the layer, Mode >BW indexed, color invert the result for knitting using the tuck double bed setting
The yarn used in this swatch is a 2/20 coarse and unevenly spun wool, which leads to the variable moiret-like bleed-through of the fabric colors behind it.  The same yarn was then used double-stranded. Some spots were harder to knit than others due to changes in ply quality resulting in snags in texture as well. The shapes are more clearly defined, the largest shape measures 7.5 inches of the 11-inch swatch width and 3 3/8 inches in height. This swatch began with a 25X25 pixel file, processed in Arahpaint drawn in repeat using the random >preview option until a final version was chosen and rendered double-length. Brush fill was used to expose every other row, and the resulting 75X150 file was color-inverted for use with the tuck setting These knits produce a subtle texture easily on both sides and lie flat.

This design is not suitable for this exercise but is another illustration of the horizontal/vertical striping that can happen when large-scale designs repeat proving the need to tile the patterns before knitting them to visualize whether they meet one’s personal preferences
71X64

Using programming with punched holes or pixels in other ways:
Using punchcards (3) or electronics to track small cables in pattern
Using  punchcards to track cables and twists in pattern 2
Using punchcards to track small cables in pattern (1) 

Unconventional uses for punchcards 3: lace in rib
Unconventional uses for punchcards 2: thread lace cards for filet mesh 
Unconventional uses for punchcards 1: tracking racking positions in ribbed fabric

ArahPaint in knit design 6: color separations

WORK IN PROGRESS

Update releases after this post was published
ArahPaint April 23, 2025
Gimp March 16, 2025 has many menu and command changes, perhaps making some reinterpretation necessary when following previously published blogposts. A quick tutorial, and a video one.

I remember graph paper, colored pencil, acetate transparency days, and the achingly slow first experiments using Excel to attempt to fill in motifs cell by cell, row by row. A better understanding of knit structures evolved along with tools to make them possible, and the process has become quick and satisfying when those black squares or punched holes make the planned knit fabric possible.

More separations for various knits using Gimp, color to alpha included this method for knitting each color in each design row twice. I have not duplicated the process using ArahPaint in the past. The previous failed attempts appear to have resulted from rendering a color transparent before copying and pasting the chosen file on another in a new window.
The experiments that follow use the same repeats explored in the Gimp posts, which included the knit swatch proofs of concepts following their use.

At the bottom of ArahPaint in knit design 5 exploring rendering colors transparent began with creating and saving one or more brushes in 2 colors and involves steps in multiple open windows.
The brushes need not match the design in width, plan its magnification and size for easy visibility ie this 12X2 A reminder: magnification used appears at the top of each window, selecting 0 on the keyboard will enlarge the starting image X1000, use select + or – for custom values  From the Kinder book
1. a 12X18 repeat
2. the published separation for knitting as a mosaic
3. #2, color inverted for knitting using the tuck or slip setting
4. the brush used to bucket fill a 12X18 picture, and the palette window illustrates each of the 2 colors alternately rendered transparent 1. in the first window, open the 12X18 PNG2. in the second window, Colors >Invert all 3. in the third window, 12X18 filled with the brush pattern A. copy # 3, as you move to paste #2 before moving it permanently in place, shadows of both brush colors will be slightly visible, select the color for row 2 and even rows in the palette window repeatedly until it is shown as rendered transparent (color to alpha)
B. paste the result in place and select the merge down/drop selection tool by clicking on its icon in the toolbox, pressing the Command+d  on the Mac Keyboard, or right-clicking outside the selection somewhere in the background image to merge the selection into the image in its current location. The dotted lines, sometimes referred to as walking ants, will disappear.
C. copy B, repeat the process positioning it on A, rendering the purple transparent to complete the color separation.

For knitting as a tuck or slip-stitch mosaic, the 12X18 file must be doubled in height to 12X36. The approach for developing separations for large-scale mosaics is the same, taking care that when images are pasted from one window to another, they are not placed a row or a column off.
From a free online pattern, the adapted repeat:  the repeat, 100X100 color inverted same size image brush filled copied and pasted on color inverted file, after light blue color to alpha copied and pasted on the original, after purple color to alpha rendered double length (or set the double length button in the machine) Proof of concept swatch found in Color separations for larger scale mosaics and mazes
DBJ work: using Stitchworld # 548 is a 24X40 design The three ArahPaint windows.  To be separated for use in DBJ with each color in each row knitting twice, begin with # 548 doubled in height to 24X80 invert colors copy the 20X80 brush-filled image, and move it in place over the color inverted file, blue to alpha, merge layers copy and paste it on the original rendered double height>20X80, first changing purple to alpha, merge colors, set the number of colors to 2> BW, the 24X80 file doubled in height (Multiply YX2) to 24X160, matching the Gimp results. Duplicating the punchcard design separation for knitting each color in each design row only once, the original methods followed using a shifting template, as follows:
the original 24X6 complete row of repeat is doubled in height to 24X12 and in turn, is repeated to an adequate height for the punchcard to roll smoothly in the reader, 24X36.Begin  the color separation by creating a 4-row brush in 2 colors ie May 2025 edit is the result of a lightbulb moment when attempting to answer a FB question shortens the process:
the new brush 1: first window, 24X36  2-3: in the second window, open another 24X36 file, color invert all content4: in the third window, open a new file, 24X36, fill with the custom brush, and select all 5: copy and paste the brush-filled image on the color inverted one after rendering the bottom color transparent using color to alpha, merge to new content 6: copy and paste it on the first image after rendering the cyan color transparent, merge the content for the end result. If preferred, save a scaled result to print and aid in tracing and marking a card for punching.
The “old” method,   
and the “new”, resulting in a matching result with fewer steps, with both matching punchcard separated the low tech way: The approach used to emulate pile knit designs using a large scale repeats as seen in Geometric shapes on ribber fabrics formed with tuck stitches 4, where proof of concept swatches are also found. Using the same design for embossed fisherman rib A 25X25 pixel file based on Truchet tiles was drawn in repeat using the random >preview option until a final version was chosen and rendered double height. A 2-row brush fill was used to expose every other row, the resulting 75X150 file.  was color-inverted for use with the tuck setting. Before being color inverted, the above design could be used in single-color drop-stitch lace or punch pile in machines with that capacity.
The spacing between lines of pixels can be varied for custom designs ie in the hand-formed loop version of a 24X48 file, adjusted in height and width by multiplying YX3 and multiplying X X2 the saved brush set the number of colors to 3 to include the added one used in the brush
in a new window open a new picture 48X144, fill it with the brush, and copy and paste it onto the first image, after rendering the third color transparent.   Set the number of colors to 2>BW, and the final 48X144 file will be ready for knitting. A new large-scale mosaic using the same approach, 32X86 PNG color inverted 32X8632X86 brush fill copied and pasted on color inverted file, white color to alpha copied and pasted on the original file, purple color to alpha double length for knitting using tuck stitch setting single bed, 32X172The swatch was knit on 60 stitches and for 182 rows, measured 9X11.25 inches. Multiple color drop stitch lace using img2track and more includes a cumulative list of links to previous posts investigating the technique including when using only one color. In Passapese the knit was often referred to as summer fair isle.
Shorthand for ArahPaint steps for attaining the same results as with the Gimp color separation: Other effects can be obtained using DBJ color separations, which knit each color in each row twice. An easy variation is seen in the post on Long stitch Passap and Brother DBJ design using thick and thin yarns.
ArahPaint drawing in repeat facilitates half-drop and brick variations of designs. Color separation often requires long images.
If a source separation is already available, ie this 40X80using offset it is possible to develop a brick repeat, 40X160 half drop repeat, 80X80 A proof of concept swatch has been added to the post on Long stitch Passap and Brother DBJ design using thick and thin yarns

ArahPaint in knit design 5

ArahPaint links
https://www.arahne.si
https://www.instagram.com/arahnecad/
https://www.facebook.com/arahneCAD/
https://www.pinterest.com/arahne0183/
https://www.youtube.com/user/arahpaint4#p/u

When this post began, I was working using ArahPaint Version 6.0.3688 on an iMac with an M1 chip, OS Sonoma 14.5, now upgraded to OS Sequoia 15.01.
Since the blog is a living document, I often add new tests or ideas to older posts, which can become quite lengthy, so this is intended as the home for the most recent observations and experiments.  The tool  has been demonstrated in many previous posts including in the early ArahPaint meets Gimp in knit design 1
and Developing designs using pattern fill for use on a range of machine models
A different approach for varying any original design, which reminded me of the drawing in repeat option in my old Stitch Painter days :
choose a repeat ie this 10X12 one. Load the picture, from the pull-down Colors >set the number of colors 2, BW palette, press the r (small case) keycap on the keyboard, and the file will be multiplied in a fixed tenfold of both height and width
make the following changes in sequence
A: the original tiled by the keyboard command r to 100X 120 pixels
B: use a single-pixel pencil, place single dots with the mouse, and release the mouse button
C: select the empty circle icon, and with the mouse click and drag to superimpose the chosen size in place on the previous design, release the mouse button
D: select the filled rectangle icon, and with the mouse, click and drag to superimpose the chosen size in place on the previous design, release the mouse button As a first option, use Tools > Find repeat, for a return to the smallest repeat unit matching the size of the original, and save the result.
A test with an 8X14 design with a superimposed filled oval The find repeat step can be eliminated, using “Save the picture as” will automatically isolate the smallest repeat, also 8X14 is now tiled using Drawing in repeat to produce a 24X42 possible punchcard design And one more 8X14 png, repeating the steps using the color white and the rectangle tool outline for another variation.  

Subsequent files and information are now developed on my iMac upgraded to OS Sequoia 15.0 in September 2024

Developing designs using pattern fill for use on a range of machine models reviewed Pattern Fill, and introduced modification mode to custom zoom and rotate brush-filled shapes using the Command key on the Mac.
In the program’s most recent updates, there is now an Interactive Rotate and Zoom feature.
Advice from the developer: “The M1 update version is lagging. If you want to use the latest version, which allows rotation /zoom of patterns, you have to install the Intel version. It works just fine with Rosetta on Apple Silicon.”
Create a brush, save it
10X5 pixels Open a new image large enough to accommodate multiple repeats, ie 120X120.
Select the brush drawing mode
Select any filled drawing tool and the brush, the angle and zoom parameters will appear.
The standard pattern fill:  Move the mouse pointer to the drawing start position
Hold down both the Control and Command buttons while drawing with the brush to enter the modification mode
Use the mouse scroll to change the angle in both clockwise or anti-clockwise directions and zoom by increasing or decreasing its size, changing values until satisfied.
To exit modification mode, click on any drawing tool.
The design was modified to these values on a 120X120 canvas
Use Tools >Find Repeat, 111X83 Check tiling using Image > Drawing in repeat, 222X249  Building collages by using custom brush fills on colored base shapes Skipping the colored collage, working simply with brush-filled shapes working from the background then adding decreasing sizes or shapes ie these circles
It is possible to work with added colors, which will factor in the changes in aspect ratios of the patterns in the final knit depending on the yarns and knitting techniques used.
Working with brush fill planned in 8X8 pixel blocks and using View >Grid Properties to 8X8:
sometimes the brush design needs to be rotated for successful placement ie this 16X16 was rotated to a second brush, also 16X16  planning for the full needle bed/200 needles/stitches, a multiple of 16+8, using brushes and filled rectangle tool, retaining square shapes with a 4-block border followed by a 3-block one experimenting with adding/subtracting color pixels, using the pencil or bucket fill tools 184X184, also a multiple of 16+8 with 3 block border.   the 200X200 tiling in both colorways Adding a fourth color also 16X16 tiling check to 136X136 filled rectangle placed on planned block design frame, 184X184.   Varying the diagonals, a 64X64 repeat tiled to 192X192 changing the colorway   aiming for chevrons, 128X64 tiled to 256X192A small 24X24 repeat for 2 color knitting with similar diagonal movement from Working with diagonal patterning in machine knitting  

could serve as the base for added color, easy using bucket fill following uninterrupted black or white cell lines  It is now possible to drag and drop selections from the internet browser or personal files into ArahPaint, working from my stash of BW-indexed files
160X160
the image was dragged and dropped from my desktop onto a new Arah picture, 244X244, the black color became transparent by default. The base ground was used both with the default number of colors at 17 and with the number of colors reduced to 2.  I was not able to drag and drop directly from ArahPaint into Gimp, but here is the image using the Command A, Command C, and Command V commands in Gimp The original BW png altered in Gimp, rendered in 2 colors in RGB Mode and saved to the desktop with palette different from the ground 2 color pattern.  When dragged and dropped onto the 244X244 background, the result is a 4-color file for knitting using 4 yarn colors.  Here there is added patterning viewed more easily when the design is enlarged, and in the dropped file, the white pixels are converted automatically to alpha   Another BW-indexed file, 132X132 the black is retained, and the result is visually in 3 colors, with the white pixels converted to alpha  Before the dragged image is fixed, the color to alpha selection can be altered.
The final palette will contain all four colors.
When working on a project where the actual final number of colors is 3, check that >set the number of colors is on #3 before downloading the design to avoid patterning errors in knitting after downloading to KMs.  The placement of the shapes in these variations is not knit-ready.  The designs are simplified for 2 color knitting and using the built-in electronic KM separation Building patterns using blocks requires attention to eliminating or halving them if the goal is to avoid shapes doubled in height, width, or both and to meet personal design preferences.
A series of related files beginning with a 12X20 motif  24X20
24X20 color reversed 23X37 tiled to 138X148  playing with color reversed segments, 24X20, suitable for punchcard models as well tiled to 168X160 Building diagonals with color inverted blocks
16X16 color inverted 32X32 in repeat X4 Seeking triangular modules that do not intersect with multiple stitches as seen in the formerly shared truchet tiles. This motif inspiration was found in https://www.mi.sanu.ac.rs/vismath/sarhangi/ Hand building repeats beginning with colored 5X5 blocks converting all to single-color isolating the 30X30 repeat the tiled design, 150X150 A 60X60 design isolated from the 30-pixel image drawn in random, best viewed with a 5X5 grid trimmed to 58X58 eliminating areas with double rows,
A small design, 10X10,  with a few added pixels, two views of secondary shapes with the design drawn in repeat X4.  Adding a third color to form straight-line diagonal outlines of shapes and frames can help circumvent those doubled-up stitches and retain aspect ratios.
A 21X17 repeat trimmed to 21X16  tiled to 147X144, followed by a partial magnified view  A simple 24X24 two colors per row design may be varied using the fair isle setting with changing colors in the A and/or/both yarn feeders,  adding a third color per row will require a color separation It is possible to work on a block pattern filled ground, using colors to replace, add or remove pixels to produce a file for knitting in only 2 colors. A new 24X24 start Again, adding a third or 4th color in each row will require a color separation even if knit on a single bed.
These designs were generated in a spreadsheet and also rotated counterclockwise. Single repeats are bordered in red and were trimmed to avoid any double rows or columns.   A series of modules to download and play with, check that the repeat selection is not checked when drawing with them. Building a series of diagonals with shapes that can be used as they are or further edited to form secondary shapes, a starting file for DIY, providing a base for the possibility of filling in segments with added colors
38X36 tiled to 152X144 edited to keep the same general shapes but with smaller repeats: the first eliminates the single-pixel square frame, 36X36 tiled to 144X144  some pixel edits and trimmed to 24X30  tiled to 144X150 new diagonal shapes, 24X24
tiled to 144X144 forming a chevron, 47X48 tiled to 141X144 Occasionally published sources ie this from one of the punchcard volumes can be converted by using tools ie guess weave from grid and knit as provided or serve as germs for other DIY designs Using added colors only in developing designs: this repeat was shared in the post on Developing tiled repeats suitable for multiple stitch types, including tuck
31X31 now mirrored with double rows eliminated, adjusted to 60X58, with the central diamond black and white pixels selectively replaced by a single color the cyan shape is now filled with a repeat from my stash saved as a brush,    the choice could be made to clean up pixels or use the result as is. An alternate method for more flexibility in placement and less cleanup requires working in multiple windows:
in the first window draw the BW repeat used for the brush in repeat several times
in a second window, the starting 60X58 design is rendered in 2 colors select all >copy, and return to the first window, the colored image will appear over the larger black one.
Before moving it in position and pasting it in place, click on the color matching the center diamond in the palette window until the small checkered interior box appears, indicating that the color is now transparent.   Using the mouse, drag >move the smaller image and paste it in place, undoing and repeating the process until satisfied.
Select the merge down/drop selection tool by clicking on its icon in the toolbox, pressing the Command+d  on the Mac Keyboard, or right-clicking outside the selection somewhere in the background image to merge the selection into the image in its current location. The dotted lines, sometimes referred to as walking ants, will disappear.
The purple pixels are guides for cropping the design to a new 60X58 repeat.
The purple is replaced with black, the color number is verified and set to 2, and the final BW PNG is saved, ready for download  Using rendering colors transparent to achieve color separations for specific fabrics will follow in a future post.

 

Developing designs using pattern fill for use on a range of machine models

When drawing with brushes in ArahPaint 6 you can now set the angle and zoom of the brush pattern, and even if rotated at different angles, the pattern will flow seamlessly across the canvas.
Excellent videos illustrating the methods in general and new features including this one may be found on Instagram and Facebook.
Currently, though there is an Apple Silicon version, some features are being updated only for the Mac Intel one due to some issues with code signing, and  Apple finances, so to use the latest version which allows rotation /zoom of patterns, you have to install the Intel version which works well with Rosetta on Apple silicon.

Investing time in “playing” with software tools aids in finding personal methods for developing DIY designs. Who needs Wordle, or Crossword puzzles?!
The same goals may usually be achieved in a variety of ways.
Pattern fill was introduced in  ArahPaint meets Gimp in knit design 1 as a method for developing tuck designs, and a post following this one, ArahPaint in knit design 5
here the beginning goal is to develop larger-scale electronic patterns that to some degree fool the eye into visual shifts.
Reviewing and expanding on the concept: to save a brush, click on the brushes panel tab, the small highlighted stamp tool. In this instance, a previously saved brush was stored and appears automatically.  To save a custom brush, build a small file or use one from the program’s weaving library, ie this 4X6 pixel one Create a layer and send it to the brushes panel by using Tool> Layer to Brush and it will appear in the brushes panel or by clicking on the right blue triangle in the brushes panel toolbar toward the bottom right. To edit the brush you can use Tools> Brush to Layer or click on the left blue triangle in the brushes toolbar.  After editing, the new brush can be sent to the brushes panel. If the Keep checkbox is checked, the old previous version is retained To edit a brush in a new window, select a brush in the palette, click on the ArahPaint icon on the right of the blue arrows in the brushes panel, and a new window will appear with the brush already loaded. It can be edited, saved, and available in the previous window.
To delete a brush from the panel, click on its icon to select it, and then click on the delete icon, the red X in the brushes panel toolbar, or hit delete on the keyboard.
An exercise beginning with two small brushes, once again to achieve movement of lines if not a full-on illusion, while keeping in mind the repeat will be worked on a canvas no larger than 200 pixels. To follow along, working in a chosen palette, begin with a filled rectangle in a base color, 60X60 pixels.
Select brush drawing mode Choose the filled rectangle drawing tool, select the brush, hold down Ctrl (Cmd on Mac), and draw the brush across the canvas.
The relevant settings and alternating 2-pixel brushes
For the circle, repeat the process, choosing fill from the center first from the menu on the right  reduce the palette to BW, clean up the edges

to expand the design, draw it in repeat, offset 28 pixels 120X120

Tools > Find  Repeat > 60X114Tiled to 180X228  The shapes and their placement can be varied, using the same general ones helps the eye recognize differences and develop sequence in design preferences.
Here single-pixel vertical and horizontal lines brushes were used on a 60-pixel canvas, then cropped to 54X51 Adding another shape, still 54X51Developing brick repeats The respective 54X102 files  

Removing pixels from 4X4 blocks, beginning with a 30X26 quarter repeat select the empty circle tool, the pixel color, and check off   The cyan pixels are for convenience, and will be changed to white in the final designs
View > Grid Properties may be adjusted to block size and for increased visibility.  mirrored horizontally, 60X26
drawn in repeat  to 60X52 with blocks added for proper alignment to 64X64 its brick 64X128 companion
it takes a bit of squinting to see the subtle effect  

More adding and subtracting pixels from small blocks and starting with quarter shapes:
in a first slow look at some of what can happen with a bit of math and multiples of 3X3, the black pixels are added to selected spots, the magenta will be swapped to white, with the ultimate plan to end up with a black and white png, measuring 39 X39 pixels in width. The abbreviated visual summary: the associated files: 20X20
mirrored X-1, 39X20
drawn in repeat, 39X40 working between 2 windows, open a new picture, 39X39 in the second window. Use rectangle tool in the first, selecting half vertical segments, and copy and paste on the new file eliminate one of those two doubled central rows, 39X39 In a new window, open a new picture, 48X48, (a multiple of 6), fill with pattern  copy the 39X39 image and paste it in place, it is not necessary to reduce any color to alpha, the final 48X48pngdrawn in repeat, BW, 192X192Achieving a similar file more quickly and easily a 6X6 pattern is saved Using brush fills, begin with a 20X20 picture, using the 6X6 blocks, selecting the filled square icon, place blocks from the upper left corner down, it is not necessary to fill the wholecanvasusing the 6X6 color pattern, the filled circle icon, selecting fill from center, begin in lower right corner, filling the quarter 20X20 shape   mirror X-1 to 39X20draw in repeat as in previous patterns to 39X40 eliminate one of the 2 center rows, to 39X39 working in separate windows or selecting either half, ie the top, move it down a row, and rop the extra top row  4 magenta pixels added to the repeat the file converted to indexed BW copied and pasted on a 48X48 checkered ground A visual summary of the steps The file drawn in repeat to 192X192 Similarities, and differences in density of markings by the addition of single pixel lines, playing with what ifs:
the last 48X48 image, all pixels to red rotating 180 degrees in ArahPaint shifts the design one row down, and one column to the right while using Image >Transform > Rotate 180 in Gimp white color to alpha with the result copied and pasted onto the alternate 48X48 repeat.   All pixels to black/white in a new 48X48 drawn in repeat to 192X192 the brick 48X96 version,    also drawn in repeat to 192X192  the 48X48 checkered ground is cropped to 45X45 drawn in repeat to 180X180,  and what of that 39X39 design that started so much of this? trimmed to 38X38 drawn in repeat to 190X190 Returning to smaller design repeats, testing modification mode zoom and rotate:
open a new picture, 60X60
draw a repeat and export it to Brush, ie 7X7 select the brush drawing mode.
choose a filled rectangle drawing tool
select the brush, hold down Ctrl (Cmd on Mac), and draw the brush across the canvas. release Cmd key; the program is in modification mode.
set the angle and zoom manually by typing in values, or holding the mouse pointer on up and down arrows,    while observing how the image changes in the main window to exit the modification mode, click on any drawing tool
use Tools > Find Repeat > 24X52check alignments, 154X156 The same brush, 60X60 filled canvas Tools >Find Repeat > 21X1 check alignments, 147X147 Working with small identifiable shapes: 80X80 canvas, repeating the process with an 8X8 repeat standard rectangle fill: use the command key on Mac, Angle 60, Zoom 200 find Repeat, 47X47 check alignment, 188X188 It is possible to overlay brushes using a series of them while working in multiple windows, my choices are random when testing concepts.
The first brush, 7X28 pixels,  the second, 8X8and the third, 60 x60 with white color to alpha The first brush is used to fill the first square, 60X60 In a new window, fill a matching size 60X60 square with the second brush To render a color transparent aka color to alpha, in the second window, below the palette icon, select the white color icon repeatedly until a checkered box appears in its center indicating that color is now transparent  The transitions: from the filled square, to the same with the white color to alpha, and the layer saved as a brush Use the 60X60 brush to bucket fill the very first square for a combined pattern and use Tools > find repeat, with the result: 24X48 The color inverted design: the appearance of both in repeat Working with diagonal patterning in machine knitting previously discussed some ways to obtain such patterns.
Developing diagonals using 45-degree angles and brush fill with pattern, using files matching in width and height, this began using a 12X12 image on a filled 100 X100 pixel canvas, and using Tools >Find Repeat X2 produced the final 17X17 design.
The process in shorthand:
the 17X17 png, also shown drawn in repeat to 102X102 Testing the same process on a canvas with a multiple of 24, 120X120 with a new brush also yields a 17X17 final repeat drawn in repeat to 136X136 The results are consistent when the approach is used on smaller canvases, here on a 40X40
Using multiple colors in uneven spacing also yielded a 17X17 final repeat checking alignments, 119X119

Some other effects with pattern fill:
dithering 

Developing 24 stitch optical illusion patterns for use on punchcard machines and more.

I have recently become obsessed with designs that fool the eye in any number of ways, and although knitting them in more than 2 colors is possible, I prefer the ease of only using 2.
Floats are likely to be too long in these knitting patterns for knitting them as single bed fair isle.
Software facilitates but is not necessary to develop repeats, the process may even be performed on graph pater with colored pencils if one so chooses.
Punchcard machine users are not always included in conversations, this post  addresses some ways of developing full 24 stitch designs and performing the necessary color separations for knitting them as DBJ where each color in each design row knits only once.
Brother KMs: punchcards and their use  reviews the basics including DIY development of simple motifs repeated in symmetrical tiled patterns.
The Manual for the Brother KR 830 offers this advice on DBJ knitting: Using lili buttons along with the slip stitch setting in both directions on the ribber carriage reduces motif elongation and keeps the aspect ratio of the planned designs closer to that in the originals than when choosing other DBJ techniques.
Ribber needle tapes are marked with lines followed by spaces. If the start under the first ribber needle on the left is on a blank space on the needle tape, simply end on the right with a needle over a line marking, or the reverse.
I am often asked why in my own illustrations the slide lever on the ribber carriage, a Brother “thing”, is always in the center position.
Reducing variables exponentially reduces errors.
If the lever position is not changed after those first rows or accidentally changed during knitting, the knit gauge will change. An example: working on final projects, more than one student in my knit studio design classes realized only after completing front and back or the second sleeve that the rib with the alternate lever setting not changed resulted in a visibly different rib height in the second piece.
Necessary adjustments can be made in yarn mast and respective carriage tensions, along with yarn choices appropriate for the technique.

ArahPaint and/with/or Gimp with a sprinkle of Mac Numbers have become my preferred go-tos for developing knit designs.
Designing can begin with simple drawings which do not require complex software knowledge and help to build confidence, using the electronic equivalent of graph paper and colored pencils.
Beginning with ArahPaint, with the goal of developing a 24 stitch pattern: load a new square picture, with an odd number of cells, in this case 13X13
Choose from the default palette, or set the number of colors to 3 and adjust the the results to include white, black, and one other clearly contrasting color Draw some starting lines/shapes that can be outlined with single pixels pencils Using the single pixel pencil tool, fill outlines in with color 3 To eliminate double pixels, mirror the image using the 25X13 pngrepeat mirroring using the 25X25 png Using the rectangle select tool, again to avoid double pixel lines, trim a row from the top and the right side of the design the 24X24 cropped result tiled as is with with the palette reduced to black and white The question remains as to how best to knit similar designs on any machine.
The floats are too long for FI, the repeat is best suited for DBJ.
The easiest color separation for DBJ is the one where each color in each design row knits twice.
To have each color in each design row knit only once, electronic machines offer the KRC button. The same result can be obtained in punchcard knitting by custom color separating the design.
When knitting DBJ with these separations, the 2 most common causes of stripes on both sides of the fabric are beginning the preselection row on the right, rather than the left, or as in my swatch, forgetting to push in both slip buttons.
This separation process for me is a very quick one using Gimp, I have not yet sorted a similar one in ArahPaint.
Using color to alpha as described in previous posts, the required files:
24X24 BW
24X48
24X48 color invert
24X4 with the top rows in a color picked from the program’s built in palette. Use Colors, white to alpha, to render the white see through. Copy the file to the clipboard, and use it to bucket fill with pattern  a new 24X49 (col inv png 48+1 blank row at top) bucket filled with the clipboard patternthe pink color to alpha, renders it see through, th last row is cropped, to 24X48, and is copied and pasted on the original 24X48 imageThe proof of concept swatchIf you enjoy designing with pencils in paint programs, the same approach can be used to produce a larger repeat, which makes the illusion more noticeable, ie in this 36X36 design.
Open a new window with an odd number of cells,  ie. 19. Copy and paste the upper left of the design on the new upper left corner, keep filling in linesRepeating the steps described previously, the 19X19 png is mirrored -1 in both directions, and trimmed to a final 36X36 design Modifications resulting in added shapes beginning to appear can be small in developing variations while continuing with the 24 stitch constraint.      Repeating the process, the files in sequence   The proof of concept was knit using the color white for the first preselection row to the right and as the first knit color row to the left, the color inverted version of the original repeat.  The KRC electronic separations are intended to begin with the white pixels in the designs, but the knitter can change that sequence based on their preferred placement of dark vs light colors.
Visualizing the reverse color placement in a knit swatch using Gimp  Mosaic and maze knitting, also known as floatless fair isle, has been discussed in many other posts.
The appropriate color separation shares much of the process with that for DBJ but the starting image is used as is, not rendered double length to start with.
The convention is the same as for fair isle, floats wider than 5 stitches are generally avoided.
In the 40 stitch design, there are spaces as wide as 15 cells with no contrasting color ones, which will be responsible for float formation.
Answering the “what if” question if the 24 stitch design design was used as a possible maze design.
The Gimp process in shorthand While the DDJ separation is used as is, this separation must be rendered double length in order for it to be executed single bed with the knit carriage set to slip in both directions, and color changes every 2 rows.
Using color invert on the final file, reduces the white cell, skip stitch float counts from a maximum of 15 to one of 6. Tiling will check on repeat alignments but has no relationship to the final look of the knit, where the slipped stitches will be gather the knit ones near them. The resulting swatch is highly textured, some of those extra long slipped stitches could be amended by making small changes in the design if it were to be developed further.  

For electronic models, the second 24 stitch repeat extended to 30X30
36X36  

ArahPaint in knit design 4 illustrates a way where following guidelines in Easily generate random weaves it is possible to quickly generate more random DIY designs for use in multiple techniques and stitch counts.

DBJ, more than 2 colors per row 4

Revisiting older posts often brings to mind new or slightly different ways of looking at and achieving the same tasks.
Links to some related previous posts:
DAK DBJ color separations, templates, and other software
Revisiting Ayab_multiple colors per row DBJ 2
Revisiting Ayab_multiple colors per row DBJ 1
Img2track_multiple colors per row dbj, each color knitting only once
DBJ: more than 2 colors per row 3
DBJ: more than 2 colors per row 2   img2track
DBJ: more than 2 colors per row 1
Color separations for knit designs in only 2 colors are more straightforward than those for 3-4 colors.
The built-in KRC function in Japanese models will yield results automatically where each color knits in each design row only once, reducing the elongation in the designs often seen when employing other techniques.
Japanese machine models for home use (not the semi-industrial ones) have a color changer that resides on the left, and aside from whether each color in each row knits once or twice, the combined carriages need to move to and from the color changer on the left for each color selection.
The color-changers for brands differ slightly and matter in cross-brand use if one relies on published separated designs and pictured swatches.
Yarn changers for:
Brother Studio Sometimes the placement of the colors within palettes will result in the colors not being read and downloaded properly.
As described in the Ayab post: when using each color, it is coded in a range of 8-bit values. For 4 colors, it would be 0-63 color A; 64-127 color B; 128-195 color C; 196-255 color D.
When only 2 colors are in use, in manual color separations, the ultimate goal is to produce BW-indexed PNGs. They are then downloaded and programmed as one would FI patterns, palette placement is not a concern.
Working in default or limited palettes produces familiar visual clues in DIY, to save custom palettes see ArahPaint and Gimp in knit design 3 
If the goal is to imagine the results in colorways based on yarns planned for use in the finished piece, that can be easily achieved after the fact.
This design has been used in past posts and is 6 stitches wide; hence, repeated X4 in width will also be suitable for punchcard machines. Looking at it again:
checking alignment when tiled Stitches on needles not worked on the top bed are held while stitches in the other color(s) knit, and get longer. Some degree of alteration in the aspect ratio in the appearance of the design on the knit side in the final result is to be expected, also influenced by the addition of varied knitting techniques and carriage settings.  Methods I have explored in DIY repeat the same color sequence throughout even when any one of the colors is not represented in that design row: one way to decrease the visual lengthening of designs in dbj is to eliminate a row of knit stitches from each pair of passes by pushing Brother’s preselected needles back to the B position on the top bed before knitting from the right back to the left, thus skipping all needles in work on the top bed.
The HOP separation in Ayab performs this function automatically in addition to shuffling around repeat segments while keeping a fixed color rotation, making repeats that fail with other separation methods knittable.
In images where not all colors are represented on every row, there are more knit rows on the ribber than on the main bed, even with birdseye backing, another added cause of stitch elongation observable on the knit side.
When using birdseye backing, the ribber will knit every other stitch, alternating needles on each pass. An even number of needles is required. Patterning is akin to using a 1X1 card on the knit bed.
By the time the carriages have returned to the left only one row of knitting on every needle will be completed on the ribber.
The setting is not available in every model machine, including very early Brother ones.
When knitting in tuck or slip stitch, stitches grow in length until they are knit off again. This remains true when working in DBJ fabrics as well.
Yarn and tension choices can affect the final appearance.
There will be some degree of bleed-through behind the elongated stitches.
Blocking also influences the final appearance of the completed knit.
Exploring possibilities:
The initial 6X6 file is converted to stp and opened in DAK resulted in the following messages and pattern error corrections A second design was also tested in DAK and yielded the same error messages:  The 6X6 stp doubled in length to 6X12 cells allow for the option of selecting the type of dbj color separations, creating files that can, in turn, become PNGs for working outside the program, and for printing traceable templates for punchcards. That work is achieved through hacks since DAK does not allow direct import or export of file formats other than its proprietary ones ie stps or txt for use with Kniterate.    A closer look at the diagram of the color sequence options in each
The characteristics of the more commonly used methods in review:
Method A works on pairs of rows, Method B creates the same separation as the default built-in KRC one in Japanese electronics with each color in each design row knitting only once, Method C separates each color row into separate rows of knitting, rows do not have to be repeated in pairs in DIY, and the double-length switch will need to be used in Japanese knitting machines It is possible to generate an output of the separation and to process it to generate files usable in img2track or for printing traceable punchcard templates.
The program does have an option to save a bmp but the save is of the separation on a grid with added data, not as a file immediately usable in other programs. Click on the floppy disk icon outlined in red to save as bmp as an alternative to screengrabs.   Using the same 6X12 file, the generated printable templates and associated converted PNGs:
A B  the repeat here is also for the original lengthened X2, and 36 pixels high with no segments repeated. The essential difference is that the first preselection row is made from left to right, with the pair of rows for color 1, design row 1 split between the top and bottom of the separation.  C

elongated X2=24X72, handy for other knit structures, but not for reducing elongation in DBJ Using img2track set at knitting in 3 colors, there is no error message, but the 6X6 file will not produce the planned design.
A proof of concept is provided in the post DBJ: more than 2 colors per row 2. Starting with the double-length 6X12 file, each color in each design row will be knit twice:  and the machine will offer prompts for its pre-determined color change sequences.
Most recently, my separation experiments using Gimp use transparency methods and are are shared in the reverse order of their development 
#3 The briefest and last method: working in RGB mode, begin by multiplying the pattern in height X3, to 6X18 Isolating the red color on a white ground:  isolating the yellow on a transparent ground:  isolating the blue on a transparent ground: copying and pasting the isolated yellow and blue with transparent grounds in  turn onto the red design isolated on the white ground
changing all 3 colors to black
doubling the image in length to 6X36
remove every second row using the pencil tool or bucket fill it with the 6X2 pattern, and change the cyan to white. Any other color can be used instead of the magenta at that point
change Mode to BW indexed, and save the final file for knitting.   Comparing the results for the full repeat from other methods on the left, with the one using this method on the right

Returning to that 6X6 repeat that was prone to error in both DAK and img2track, with each color represented once in each row, exploring the possible separation to knit each color only once, and using a final 6X18 PNG led to patterning failure.
The Image menu progression of its process in Gimp: the number of thumbnails grows and one can travel through the images using simple clicks until any image is discarded or the program is quit, the X appears aside the file viewed in the work window.  Each color was isolated on a white background, with guides placed horizontally across every pair of pixel rows.  Pairs of rows of each color were copied and pasted in alternating sequences on an all-white file longer than 18 pixels rows and the results were trimmed to a 6X18 file for a knitting test.  Though the built-in KRC separation takes that first design row and moves it to the top of the repeat, thus knitting a single row with color 1 and completing it in a pair on the last row of the program, the first knitting test began with preselection from the right, and color 1 knitting for 2 rows.  A second try at an 18-row repeat, also a design fail, with odd breaks in the lili action on the ribber, seen in Passaps when pusher selections on the back bed are disrupted.  When the motif was doubled in length, and the same method was used, the results matched the 24X36 file.
The 6X6 design, however, expanded and separated to a 6X18 file may be used in machines with color changers on each side, with a different color sequence, see DAK Method E notes toward bottom of post.
#2 Working with the 6X6 design lengthened X6 to 6X36

with every other row rendered in all white cells The proof of concept swatch

DAK owners see the 36-row file and similar knit sample for the Half Milano separation F toward the bottom of the post.
In my #1, first separation draft, the 6X10 file is elongated X6, to 6X60, considering that each color in each design row will be carried for two passes.  The latest Gimp version for Mac is 2.10.36
Sometimes there are differences in commands in the Windows version.
Begin the work in RGB Mode.
The color-to-alpha command in Gimp makes all pixels in a selected color transparent.
The option can be activated through the Layers Menu by choosing Layer> Transparency> Color to Alpha or the filter via Colors> Color to Alpha from the pull-down menus at the top of the work window.
No threshold or blending adjustments are needed in the small 8-bit files used in designing knits.
Some previous repeats using  colors to alpha in 2-color separations can be found in the posts
Color separations for larger scale mosaics and mazes 
and on Using Layers in Gimp for Color separations
Magnify the image to a comfortable viewing size, ie 800% or more.
When the color to alpha dialog window opens, there will be a small preview of the image you are working on on the upper right that relates to how many images are available for processing in the work window at the time.  When the color white is in the mix using the 8-bit files, the preset color selection for transparency in the color bar is white.
To change the color selection, click on the white color, the palette window will appear, select the new color, and click OK.

To Bucket Fill with pattern: create a custom brush size, matching the starting design width in pixels. The number of rows varies with intent. White is used as one of the colors, and the second color can be any other.
Click on the rectangle tool and then on the pattern thumbnail, an icon for it will appear on the upper right of the work window. The brush will be copied to the clipboard and will be available to use to pattern fill until the program is quit. It can also be saved for future use as explained in other posts.  To fill specific groups of pixels with FG or BG colors, click on the select by color tool,  and then on the color you wish to change, use bucket fill, selecting foreground or background color.
The fuzzy select/magic wand tool mentioned in previous posts is designed to select areas of the current layer or image based on color similarity. It appears to the left of the select-by-color tool. It can be used when pixels in that color need to be changed in contained single areas rather than throughout the whole image.
If using the bucket fill with foreground or background color alternating with fill with pattern, remember to switch between the two as needed.
If an error is made, use Image> Edit> Undo to move back to any previous steps.
If at any point the image in the work window is surrounded by dotted lines, click on the rectangle tool and then again in the work window to essentially fix the layer.
The Image menu provides access to nearly any operation you can perform on an image.   Clicking on any one of those images will produce a dotted outline around it making it identifiable and usable in work such as for copy and paste followed by bucket fill with pattern,   or for navigating between series of open files.
#1  the longhand first practice run began with the 6X10 file multiplied in height X6 to 6X60. Good practice for sorting out a technique, but guessing the aspect ratio in the final knit would be bothersome.  1. has the first 2 of the 6 design rows rendered transparent, so when used to fill the original, only rows planned for color 1 are left exposed
2. will leave design rows 3 and 4 exposed for color 2
3. will leave design rows 5 and 6 exposed for color 3
Repeat these steps on the original design 3 times, and save each completed step until comfortable with working on several files open at once.
A. select by color, bucket fill each with white except for the color red
B. select by color, bucket fill each with white except for yellow, if the color seems too hard to identify, change it to another
C. select by color, bucket fill each with white except for blue. The red and white in the last step in A are left undisturbed, while the white background in the last steps in both B and C is rendered transparent, as seen in 2 and 3. Both 2 and 3 are copied and pasted onto A, rendering the final tricolor image, 4.
Using select by color and bucket fill, the three colors are replaced with black, 5.
A last brush bucket fill, 6, leaves only the first row of black cells exposed, changing the cyan to white and converting the final result to BW-indexed mode, 7, is saved for knitting with each color in each row knitting only once.  When all 3 colors are not represented on every row,
The 11X10 image was used in previous posts,   tiled,   the tiled elongation:  The separation uses method#3:  the process with the image lengthed X3 to 11X30 representing each color in each design row once:  working with Gimp transparency, isolate the red, retain the white ground isolate the green, render it on a transparent ground isolate the blue, render it on a transparent ground,  copy and paste the green and blue rendered on transparent grounds onto the red on the white ground initial image, obtaining a 3 color separation.
Replace colors with black. For knitting each color in each design row for 2 passes double the file in height to 11X60 pixels. To knit each color only once in an attempt to further reduce changes in aspect ratio, erase every second row. Images for knitting are saved in BW-indexed mode.  The DAK template (set for 950i) and img2track screen image compared to my result:  the 11X60 PNG, all pixels, 
and with black pixels on every second row changed to white The proof of concept swatch: the vertical lines between pairs of stitches result from the drag on the ribber stitches to the right and then the left as the birdseye pattern is formed, they are frequently also seen in ladderback dbj.
The yarns used are not of equal thickness.
Balanced yarn weight and tighter tensions would diminish both those lines and any bleed-through behind the stitches on the knit side.
The dropped stitches on the purl side indicate the need for troubleshooting the condition of ribber needles and their latches.Img2track_multiple colors per row dbj, each color knitting only once used the same 11X10 repeat, explored the results using HOP, pushing needles back to B manually EOR, and a color separation with the same 11X60 final file. 
An additional way to decrease changes in the aspect ratio of the original design
relies on eliminating as many passes as possible, by eliminating design rows with “no color” out of the color change rotations.
The color changes in continuing identical sequences vs skipping any one of the colors from the rotation when not in use:  The 11X60 repeat is now to 11X48  its companion with every other second row of black cells erased.  Both create the need to track what color to use and when. If the machine or software cannot provide prompts and reminders, a spreadsheet is easy and quick to create, listing colors and corresponding row counts:  Tracking those shifting color changes is more than my bandwidth and patience allow.

As I was working on this post, a friend asked about the separations for 3 color designs in the StitchWorld Pattern Book #3.
I randomly chose # 484, with the swatch pictured on p 57 and the design separation repeat found on pp 96-98. The shortest segment can be quickly converted to a knittable 140X50 PNG. Other factors to be considered and examined:
the color-changing sequences are provided on each side.
Each design row appears different from the row below it, raising the question as to whether each color is knitted only once.
The built-in KRC function in Japanese electronic machines automates that option when only 2 colors are used.
Passap E6000 users have a programmable reader technique that accomplishes the same for 3 and 4 colors.  This SW III segment is for rows 521-570, p98, with two more full pages in the pub beginning on p 96 with rows 1-260, and p 97 with rows 261-520.
Gimp Guides were placed on a screengrab of the file and it appeared each number was associated with 2 design rows.  The color numbers are not in fixed sequences and differ on each side, as seen in this magnified view.  Found when browsing through the SW III pub for added clues: the fair isle section symbols are suggestive of the CK35 Brother semi-industrial machine, produced in small numbers decades ago. The CK 35 has a color changer on each side.  From the manual regarding their use:  If the files are intended for the CK 35, additional information is needed for emulating or adapting them for use on home knitting models, not always possible.
The same is often true when traveling between machine brands manufactured in different countries.
DAK owners can use Method E jacquard separation for machines with a color changer on each side, like the Brother CK 35. According to the manual, the process works on pairs of rows and separates each row into a pass with each color.  A sample separation with no error messages when the 6X6 file is opened.   Untested DIY for the same separation:
The 6X18 repeat opened in Gimp, using a single-pixel pencil to fill in all except the color for that row with white.  Using the custom brushes and bucket-fill with the pattern, begin with isolating the red color, retaining the white background,  repeat to leave the isolated green exposed, and convert the magenta color from the brush to alpha repeat with the isolated blue,   in two steps, copy and paste the green and white on alpha and the blue and white on alpha on the red-on-white ground image, the tricolor final result, which matches the result from the pencil color replacements, is then rendered in BW for knitting. The last DAK Method F is referred to as suitable for Half Milano. It is directly translatable for use in the Japanese models.  The corresponding separations for both the 6X6 and its elongated sibling, 6X12 The 36-row repeat was quite different from mine, but a knitting test resulted in a matching result while trying out the 11X10 design in DAK resulted in obvious patterning fails, likely because the repeat is not an even number of pixels in width.
A repeated knit test of my 11X60 repeat, the arrow points to operator error when I failed to notice the color changer was carrying 2 colors at once. It is possible to superimpose final repeats on each other to look for errors and differences. The DBJ separation in DAK was 60 rows high as well, but it appears to be inaccurate, pointing to possible unidentified errors when working with a stp that is an uneven number of pixels in width.