Revisiting GIMP in knit design

If my only goal is to create illustrations for my posts rather than to produce programmable designs for download to any knitting machine, my go-to program in the past was Excel. Depending on my charting needs, now that Excel is no longer available to me, I am using Mac Numbers or Pages.

My computer is an iMac, with OS High Sierra installed. Last December my 910 was altered to work with Ayab, as mentioned in other posts, via a USB connection to the Mac. For generating files for download I like to work primarily in GIMP (Photoshop is no longer available to me as well). It is freeware. The latest stable Mac Version is version 2.8.22.  Windows users have an option to download  a later release . Another freeware option is Paintbrush , a smaller, user friendly program.

I began sharing my GIMP explorations in mid 2013. Some topics included charting 1, 2 , 3, color reductions for 2 color portraits , generated mazes 1  and 2 , lace mesh , lace mesh and superimposing , 2 color drop stitch lace

I am using one of my drop stitch designs throughout this post to illustrate steps taken for altering the original by using options such as scaling and tiling. It is intended as a partial quick start guide, not a complete tutorial. The program’s manual provides keyboard shortcuts etc. for anyone wanting to explore more options to obtain similar or other results. That said, the manual is not recently updated or Mac specific, and Mac vs Windows appearance of windows and menus differ.

To alter and set pixel per stitch options double click on pencil tool,  choose square single pixel highlighted in brush shape menu

to draw in single pixels, choose show grid, snap to

There are limitations as to how low the magnification may be set before the grid is visible or disappears. I often work in 1,000 magnification. The magnification value numbers, seen at the bottom of the charts in progress,  may be typed in or use arrows to scroll up and down in value 

If your document size is larger, it is sometimes quicker to work in larger pixel size blocks. Here one meets limitations

GIMP large square brushes: numbers indicate desired pixel countand if you are using Paintbrush instead, the “square” is lost

To scale images in height or width without color distortion, change color mode

Image, mode, select Indexed
choose Scale Imagehighlight number you wish to keep constant, whether width or height
to break aspect ratio and control one of the 2 values, click on chain like symbol on right, it will appear “broken”change the alternate value to the desired number

Click on scale image. If the intent is to continue editing by using the pencil tool, the image mode needs to be returned to RGB before proceeding with editing

You can verify finished image size by choosing scale image again, at that point the chain like symbol on the right of the numbers is “whole” again, awaiting further editing choices

double height double width
 scale may be performed again on the last image created 
the appearance if the image mode is set to RBG, and not indexed prior to scaling

scaling down by half for mylars or for machines that can alter motif to double wide: 

click to the right of the highlighted number, the “chain” symbol on right remains intact replace the width value, click to the right of the height value and the number will automatically change

click on scale; remember to change image mode prior to doing so if needed; on the left is the image scaled in RGB, on the right in 1 bit palette

If the image has numbers that have odd numbers in stitch width, the software makes the choice, in assigning values, since no half pixels can be rendered.  For design details see previous post 

Tiling is useful to check how repeats line up when applied to the all over surface of a knit, choosing to alter the horizontal repeat in width or vertical in height, adding borders, and other variations. Ayab software in particular, requires the individual repeat to be programmed for the number of needles you wish to knit in pattern on the main bed. Depending on the size of the original motif the tiling function may be used on nearly any scale, with or without a visible grid

To keep aspect ratio, chain like symbol on right of width and height values should be kept whole (first image). It will appear “broken” on side of values from screen grab after the image was tiled, when by pulling up the scale option again, to verify pixel counts for the newly created repeat (images 2-4)

to color invert a single repeat or a tiled one  

A Facebook Ayab Group share and tip by Claudia Scarpa  brought up a discussion on using Gimp to rescale knits with the intent of estimating distortion in the design as a result of stitch gauge. In many knits aspect ratio is forgiving. In representational knits it can start to matter significantly. I played with numbers from 3 different gauges, getting back to a simple circle square first, then following up with a much larger image. Starting with pixels per inch setting in scale menu:

doing a bit of math: if gauge is 5 sts, 7 rows, divide 7 by 5 = 1.4,  6 divided by 4 = 1.5; use the quotient (division result) to modify the respective X and Y values

keeping the X value constant, multiply the Y value by 1.4 for 5 X 7 gauge
in the view menu, uncheck dot to dot prior to selecting scale

keeping the Y value constant, multiply the X value by 1.5 for the 6X4 gauge, uncheck dot to dot if it is available in the view menuTo get rid of the math, simply switch to pixels /mm and plug in your gauge. The starting image:

change X and Y resolution to match your stitch and row gauge, breaking “chain link” on right to disable aspect ratio. In order to show the altered scaled image, the dot per dot feature in the view menu needs to be unchecked prior to selecting scale

knitting gauge 5 stitches, 7 rows per inch  4 stitches, 6 rows  per inch and going much larger, using Rocco again: the original version scaled for stitch gauge of 33 X 40

a large geometric .bmp edited with same process

Claudia Scarpa has created a document on “how to edit a picture with GIMP for “Oknitme software” that she has given permission for me to share here: 03-ENG-gimp. The tutorial has clear instructions for anyone wishing to explore photo editing  for use in knits with GIMP, and the Oknitme online tool helps punchcard knitters participate in the process.

If freehand drawing suits your needs, you may find it easier to work with view settings shown below, and adjust pencil pixel size to suit

 

 

Drop stitch lace using Ayab software

Some notes on how tubular software color separations such as the one automated in the ayab circular setting may be found in previous post

In an effort to respond to a request I have had via my blog, I am sharing information on this topic as I have time to explore it. My first attempt when up and running with the Ayab software, was to to reproduce an earlier sample I had created as a color separation originally intended for a hand knit shadow knit experiment.

a chart from that blog posttry_drop_stitchthe resulting hand knit, on purl side
IMG_0823the color separated sample knit pre ayab the sample knit using the Ayab circular setting

Patterns predawn for shadow knitting, appear to be one published source for interesting 2 color drop stitch variations. What about geometric shapes or developing your own designs? Designs created using this technique lengthen considerably when off the machine. Both color sets of stitches become elongated as they are dropped, and that should be a consideration in planning your design. If your goal is a circle, the actual shape programmed may have to be closer to an egg laid horizontally rather than that of a “true” circle. The fabric also widens considerably when blocked and off the machine, making cast on and bind off methods considerations another necessity. Design repeats may be drawn in Paintbrush or GIMP (both freeware), or Photoshop. I have been a longtime GIMP user, and prefer to use it in tiling repeats as opposed to the copy and paste features in Paintbrush to accommodate the Ayab requirement of programming the repeats horizontally in the width of your piece.

In my previous how to posts on designing your own 2 color drop stitch lace, part of the color separation required elongating the design X 2. Starting side in Ayab for needle selection always needs to be from left to right, and elongation of the motif is not required when using the Ayab circular option.

This was my first working repeat, A = repeat charted out. B = the working bitmap or png, etc. (which would be the only requirement for the mylar). C = the image tiled for the chosen number of stitches (again, Ayab requires the repeat be programmed for the width of your knit piece). D = the image elongated, not usable for this fabric, it results on too much elongation. If you would like a knit border on either side, that can be achieved by having extra stitch(es) in work on the ribber

The results up to the point in which I had a yarn caught in brushes and stitches dropping on the left of the needle bed:

Drop stitch lace has been referred to over the years in other terms as well, such as release stitch, drive lace, and summer fair isle in Passapese. Passap knitters will recognize the results from this first method are akin to those produced using Technique 185.

Getting started: stitches intended to be dropped may be created on either bed. If the ribber is used to create loops, then the technique is a manual one. Using the main bed in Japanese machines to program dropped stitches increases accuracy and ease.

If you are swatching and testing, a permanent cast on is not necessary. The broken toe cast on is one of the two quickest on the Japanese machines, usable on on either bed. It is fondly called that, because if ribber cast on comb and weights are in the wrong place so that the wrong loops are dropped, everything falls to the floor, and likely on your toes. There is an online video by Diana Sullivan that shows its use for a tighter cast on row in 1X1 rib, but the use here is for a different purpose.

In producing this fabric you are technically knitting an “every needle rib”. Cast on a fairly tight zig zag row. The ribber comb wire needs to be placed so that it holds down the stitches on the bed on which you need to keep them. The principle and results are akin to  the first row knit when you use a single bed cast on comb, and the second pass, with the first knit row anchors open loops before your continue to knit. Any loops not secured by the comb will result in dropped stitches. Any fabric, any time, when 2 stitches are empty side by side, stitches are not formed and the yarn is dropped off them creating a float or ladder.  The red line indicates the ribber wire on top of the ribber loops in the zig zag row, placed so released knitting will be left on the ribber. Black lines your zig zag yarn loops, blue dots the teeth of your ribber cast on comb. You can check placement by dropping just a few loops on the main bed before hanging your weights on the comb. 

zig zag row showing placement of cast on comb teeth, on each side of main bed needles
with wire in place, anchoring ribber stitches testing out dropping a few stitches all stitches now on ribber in preparation for dropping stitches created on main bed 

It is possible to also use a wired cast on comb for an open stitch cast on on the top bed only. Remove wire from comb. Bring the comb up and between needles to be used, and  re-insert wire. Needles and latches will need to travel easily under the wire when the first knit row takes place. 

The knit carriage will not clear the comb properly because of the location of its brushes, etc. For the “cast on” row, exchange the sinker plate on your knit carriage for the one normally used with the ribber. The first photo below shows the approximate location for the comb during the first row knit. Needles are centered between the teeth, the teeth themselves line up with gate pegs. The comb needs to be manually held in place, since there is no opposing bed in use to help balance it. Working with the ribber up would ease the process in wider pieces of knit. The ribber sinker plate has no brushes or wheels to anchor knitting on the knitting bed. Any rows knit single bed using it, will need to have needles brought out to hold position prior to knitting each row for all stitches to be formed properly

the comb in positiona pass is made slowly with the ribber sinker plate in place the comb is droppedbring all needles out to hold position knit one more row, returning to starting positionchange sinker plate on knit carriage if needed, proceed with knitting

To use the same method with ribber in place: hold the appropriate ribber comb with the bump(s) up facing you, so that the teeth line up with gate pegs as shown above, and so the needles can come through the gaps. Leave the wire in, hold the bump(s) against the ribber, and tilt the comb against knit bed. Hold the comb high enough to take the carriages across to opposite side. Move carriages to other side, drop the comb and weigh it. If continuing on the top bed only drop the ribber, switch sinker plates, and continue to knit.

“bumps”: Brother comb 

For other purposes and an edge similar to a “weaving cast on” executed on Japanese machines use EON for the “cast on row”, then bring into work and add the rest of the needles prior to knitting the second row.

Use a cast on comb appropriate for your knitting machine’s gauge ie 4.5mm, 5mm, etc., brand is not relevant, only tooth spacing is. It is possible to cut ribber cast on combs into different widths for use when knitting is planned on fewer stitches than those accommodated by their available commercial widths.

As for dropping those loops that will form the long stitches, one can do so “manually” with improvised tools. For more “automatic” dropping of stitches using knit carriage in Brother patterning, one may punch a card or draw a mylar with a method akin to color separation. A pass of the KH carriage across the knit is made with no yarn in feeder, “color 2” is actually “no yarn/empty” from left to right,  while establishing the proper needle selection on its return. The ribber would need to be reset to slip, or the ribber carriage separated from the knit one for the 2 passes to and from the color changer. This is the “scariest” option by far, more error prone. It is not applicable when using the circular Ayab setting in creating the fabric. Without a specific “tool”, all stitches can be brought to E and back to B with a ruler, piece of garter bar, ribber cast on comb, or other handy ‘toy’. Dropping stitches is done while carriages are on the left, after the return to the color changer side. It is possible to modify the Studio accessory used to drop stitches

full altered_500

For 2 color drop stitch, the main bed is set to slip in both directions. Because not all needles on the main bed are used for patterning on every row, the KC II setting on the change knob is used, eliminating end needle selection on the 910. The ribber is set to knit every row

Ayab: begin  your design repeat on your first row, choose its circular setting in machine type pull down menu on right
First design row is preselected left to right
Main bed is set to slip <— —> , change knob on KC II (end needle selection is cancelled)
Ribber is set to knit <— —> for the duration
COL: as you go from the left to right, needles are preselected on the top bed, they will knit, picking up loops that you will in turn drop on the subsequent passes of the knit carriage from right to left.

COR, the KC knits on preselected needles as it moves to the left. Clear the color changer, set up your next color. Drop the stitches knit on that last pass

It may be necessary to push those loops down between the beds before you next pass, remember to pull down on your knitting periodically,  visually check needle alignment on the main bed (all needles in B in work area)

*With new color move to right, preselecting the next row of loops
Knit right to left, picking up loops on preselected needles, change colors, drop stitches,** and repeat * to ** steps in 2 row rotations

so I want circles, here is my test pattern more like eggs, the black squares in shape appear as drawn on the purl sideshapes are reversed as drawn on knit side 

It is possible using the circular setting to drop only one of the 2 colors, whether background or shape. I began by dropping the white ground. I used to encourage students to develop a tune/ repeat in their head when regular actions needed to be taken. For me, in terms of yarn color,  it was “white, knit, drop”,  “brown =  erase (push back to B), go back”. 1: white travels to right, needles are pre selected; 2: white travels to left, picking up loops 3: on left, change color, drop stitches. For brown: 1. travel to right, needles are preselected 2: on the right, before traveling back to left push all selected needles back to B. Only the ribber knits on the way back to left, so brown will have knit 2 rows with no dropped stitches. I ran out of brown yarn, started over with the blue and white, planning on having the shape drop the stitches. There is a difference in the fabric width with the change in distribution of stitches. I stopped knitting not due to any mis patterning, but because I encountered another Ayab behavior that may be well known to punchcard knitters. Due to a yarn mast issue I moved the knit carriage back to disentangle the yarn, and lo and behold the pattern advanced a row.  Punchcard machines will advance a row with any movement of the carriage outside the edges of the knit. This was never an issue in the unaltered 910. At that point I stopped knitting. 

Not fond of stripes? prefer one color? the sample below was worked on 40 stitches in width, using the repeat charted for 56 stitches. Here decisions are made at the design phase of your repeat. For single color drop stitch use an image double length, and single setting in the Ayab software. The process is the same: *preselect stitches left to right, knit on selected needles right to left, drop loops just picked up traveling to left**, repeat from * to **. Settings are the same as for the 2 color drop stitch, but the elongation depending on the number of stitches dropped is not as noticeable. The texture in my swatch is diminished after a quick press, the yarn is an acrylic blend. The charted repeat illustrated is wider, but I worked it on only the center 40 stitches. As always in slip stitch, the black squares knit and they represent the stitches that are dropped. If you wish to create the long stitches on the ground (white squares),  reverse use Ayab Action Invert prior to knitting

the chart as viewed and explained at the top of the post

Sources of inspiration from studio publications vary, patterns designed for pile knitting make for suitable one color drop stitch. A partial punchcard repeat

from an electronic collection

and a punchcard pattern book, where markings emulate eyelets, usable only for single color knitting 

Note that in #2 card directly above, there is a solid row at the very start that is a design row (third all punched). In Ayab again, first row preselection is left to right, you will be picking up loops on preselected needles going from right to left and then dropping them. That first design row needs to have punched holes or black squares/pixels in it. The color separation is essentially done for you in the source image. Do not use circular in Ayab, but rather, use “single” setting and follow instructions for creating the fabric as described  above,  with no color changes. The blank punchcard rows match the no selection rows in self drawn color separations,

If double bed work is daunting, for a different stitch, worked single bed, that may cause interesting distortions in all knit, single bed fabrics see block stitch post.


The self drawn design repeats for 2 color drop stitch may be offset as well, resulting in colors being dropped alternately.  The design shape needs to be created in 4 row blocks in order for the yarn to make it back and forth to the color changer with both colors to complete one design row. The second pairs of rows in each 4 row block is  “erased”. In this instance as well, rows marked with black squares will pick up loops on the main bed, which are in turn dropped to create the long stitches. The second design repeat is off set to try to get sections of it to create loops to be dropped as well. The final motif must be a multiple of 8 rows in height if it is to be used as Ayab’s “infinite” repeat in length.

Color changes are indicated in the vertical strip in the center of the design. This was my starting idea

Elongation to 4 rows per block, erasing second pair of rows for each color on right. The repeat on the right may be used if only one color is to be dropped; the 2 blank rows in the design field represent stitches that will knit only on the ribber for 2 rows. No stitches are dropped in color(s) used in sequential rows of blank squares in all “white” areas of chart, including multiple rows above and below the design shape. Color changes every 2 rows continue, creating continuous stripes. shapes staggered, visually checking for placement of alternately dropped stitches 

To accommodate the Ayab preselection for the first row to be knit from left to right, move the last blank row in the design to the first row position. As the carriages travel from left to right and back to the color changer, the stitches will knit 2 rows only on the ribber. Continue knitting in steps as described earlier in post, changing colors every 2 rows. On a larger knit ground such shapes may be arranged to suit. This was my working repeat, but I used a third fewer stitches in the swatch than in chart. Note that the images will be reversed on the knit side, so if preferred, use Action Mirror to flip the image horizontally prior to knitting it

The swatch has been quickly pressed, so texture is flattened out, but I am reminded a bit of shadow knits when viewing its purl side

In an unaltered 910 with the ability to double the width of the programmed repeat, mylar users are not excluded from exploring a similar fabric. The repeat above may be rescaled to half the width,  drawn that way, and then use the twice as wide built in feature. Gimp does an “interesting” thing when scaling this design to half width, note the right side of each repeat is an odd number of squares, the left side an even. The repeat may be used as is or redrawn, adding or eliminating black squares if symmetry in each shape matters.  Paintbrush produces the same image, mirrored.

The explanation: further analysis of the original design reveals the fact that some of the pixel numbers in the design black square blocks are uneven in width. In this instance 3.5 is half of 7, and half pixels cannot be rendered, so the software assigns the split to 4 and 3.  

 

Lace punchcards meet Ayab

1/8/18 It appears I now have acquired preselection from left to right on the first pass with my Ayab software, which I have been told is its “normal”. I am revising information I have offered since I began working with Ayab if needed because of this, beginning with lace. This punchcard design is worked with each carriage operating for 2 rows, and all transfers in the same direction. The LC (lace carriage) on left, the KC (knit carriage) on right. An added note: sometimes punchcard designs as provided, not altering the repeat in any way, accidentally marking squares or pixels in the wrong spot, or deliberately starting with the LC on the wrong side, may still produce interesting fabrics. As always keeping good notes is more than well worth it. punchcard actions: transfers are all to the left (seen leaning to right on the knit side)With the first pre selection row using Ayab beginning with the LC on the left, the same transfer sequences occur as in the punchcard machine or a single repeat on a mylar

swatch knit with the LC operating on the left, the KC on right throughout

For use with the color changer, the same repeat may be used. Transfers however, now need to occur with the LC operating on the right giving the knit carriage the opportunity to travel to and from the color changer in 2 (or more, even #) row sequences. Using a punchcard, one would turn a punchcard over before inserting it into the card reader to work with the LC beginning on and continuing from the right. To achieve the same fabric using Ayab, shift the top row to the bottom of the repeat, and either mirror your image prior to importing it into Ayab, or use its mirror action in the pull down menu. The chart shows the repeat prior to mirroring, with desired actions described to its right. It is not possible to read first row from beyond the right set line using Ayab, so the LC begins on the left, travels to the right on the first blank row, selects on the second pass to the left, transfers stitches as it travels to the right again and stays there, operating from that side for the remainder of the knit. All transfers are now reversed and made to the right, and seen leaning to left on the knit side of the fabric. After the first 3 LC passes, each carriage operates for 2 rows at a time, all transfers are to the right, lean to the left on the knit side of the fabric.

Possible striping choices:  the differences between areas marked A or B is in location of the color change. In A areas the color is changed immediately after the single transfer at the top of the “triangle”, in B areas the last eyelet is completed in the same color used up to that point, and the color change is made after the first row of 4 transfers at the base of the “triangle”. More complex lace repeats create much more interesting variations in the direction and movement of the stripes.
 verification on a different day, LC on Left, repeat not mirrored 
The punchcard for  fabric from 1/25/18 post. This fabric creates large eyelets, there will be 2 empty needles side by side for the duration. Some of the old pattern books referred to it as one of the “mock crochet” ones. 

operating with LC on the left operating with the LC on the right: the repeat is mirrored  

the original repeat (re-worked on 24 sts)Ayab for operating with the LC on the left, repeat is mirrored  Ayab for knitting with LC on the right, original repeat, rows split

The bottom of the swatch was knit with the LC operating from Left, the top with the LC operating from right after its third pass illustrated  in the “triangle” lace description above repeated testing, bottom LC operating from left, top LC operating from right

A sample of weaving and lace see discussion of a punchcard to mylar conversion 
for full details. The punchcard was originally designed for operating both the knit and the LC carriages from the right. If KC I is used resulting in end needle selection  on only the first and last needles in use, prior to passes of the LC push those needles back to B. If there are 3 empty needles on the edge on either side on rows preselected for weaving, bring the outside needle to work/ E prior to laying in the weaving yarn.  The image tiled for the width of my knit, in this case 32 stitches, a multiple of 8I actually cast on an extra stitch on each side at the beginning of the piece with the intent they not be in pattern and create a single knit stitch border in areas of transfers. Here are the results, barring a couple of spots the weaving yarn did not get caught properly. The pattern as drawn produces a fabric that is interesting, but different than the intended

With the pattern flipped horizontally / mirrored, we now have the same results as in using the 589 punchcard

So to mirror or not to mirror? that is the question… I tested  643 and 650 from Pattern book #5, found mirroring was indeed required for transfer accuracy. I  verified that the “triangles” do not need to be mirrored to match the punchcard swatch. The notable difference in the latter is that all transfers are in the same direction, and that each carriage operates for only 2 rows.

Two more to try, directions are not ayab specific : a large diagonal eyelet lace combining lace and tuck 

12/28/17: tuck lace meets hand technique 

For more lace samples, and symbols and suggestions from punchcard books on knitting the fabric, please see http://alessandrina.com/2017/12/08/punch-card-book-symbols-and-samples_-wip/

A Fair isle sample with deliberately mirrored lettering proved the program knits what it sees, so my letters were still reversed, as drawn.

On 12/25/17 I shared my first try at lace using Ayab and the work around for the first pre selection row occurring from left to right. The LC is the one to select for transfers, the KC knits to complete the formation of stitches. Brother punchcards for lace usually begin with selection rows, end with 2 blank rows at their top. Because Ayab requires a first pass from left to right for the next row to be selected, to get the pattern to work one needs to split the 2 rows at the top, bringing one of them down to the start of the repeat. If knitting continues with the LC pattern as originally drawn, the transfers will occur in the opposite direction of that intended. To work around that, the image may be mirrored in the paint program before download, or use action/mirror in the Ayab menu before knitting. One nice added feature is that blank rows may be left at both sides, creating a knit stitch border, and eliminating the problem of paying attention as to whether end needles are selected or not, and what measures to take. This fabric creates large eyelets, there will be 2 empty needles side by side for the duration. Some of the old pattern books referred to it as one of the “mock crochet” ones. These repeats do not hold with first pass pre selection from the left.

the original repeatthe repeat mirroredthe resulting fabric, knit and purl sides

no mirroring, software patterning errors in one of the test swatches 
operating from the right, using the color changer