Previous related posts:
2 color ribbed brioche stitch on Brother knitting machine 1
Geometric shapes on ribber fabrics with tuck stitches 1
Geometric shapes on ribber fabrics with tuck stitches 2; knitting with 4 carriages
The last post on using Gimp: 2021/07/18/gimp-update-for-mac-2/
The method for color separation used for mosaics
The sources of inspiration from hand knitting or industrial knitting machine designs are endless. There are many features that simply cannot be duplicated, sometimes compromises can be reached that can achieve only imitations of the original. To my mind when knitting garments or long pieces the greater the degree of automation, the less likely one is to have patterning errors occur, in ribber fabrics, they are also more complicated to correct than single bed knitting.
I recently came across a pin of a Ravelry hand knit pattern which led to my return to this topic once more, including perhaps the addition of more colors. 
The plan is to create a repeat which may be knit using color changes every 2 rows. Each design row knits each color twice, so the standard built-in KRC separation is not a consideration, though the same cam settings may be used in those fabrics as well.
The required color separation has been discussed in several posts on the various forms of DBJ, a review:
The initial test repeat is 18 stitches by 44 rows, designed using 2 X 2 blocks, to begin with. How it might appear knit in fair isle: 
Transitions in charting visualizations:
A: FI repeat with pattern progression in two-row increments
B: every even-numbered row beginning with row 2 is color reversed
C: B repeat is doubled in length to 18X88 for initial samples
D: repeat adjustment for a first try at introducing 2 additional colors 
End needle selection is canceled, the first and last needles are in work on each side on the ribber knitting every row, the first preselection row is from right to left, cam buttons are set after the left side is reached. Knitting in these samples began with the blue yarn in the number 2 position in the color changer. The ribber remains set for knitting in both directions throughout, the images on the right do not reflect the amount of surface 3D textures.
with the main bed set to tuck in both directions: 
Lock settings are easier to achieve on the Passap than switching out cam buttons in Brother machines. This was knit using 4 carriages. Color one knits with the main bed set to tuck both ways, color two knits with the main bed set to slip both ways. The slip stitch reduces the width of the fabric considerably 
Here each color alternately tucks and slips. The choice of cam buttons matters, tucking first from left to right, slipping from right to left, with cam buttons set COL after the first preselection row 
This last cam setting appears to my eye to produce a texture “close enough” to the inspiration fabric. Attempting to add more colors: the repeat, D, is still 18 X 88 but is now shifted slightly. 
Somehow the slip cam button was not set, so the knit carriage tucked in one direction while knitting in the other. I am vaguely reminded of illusion knits. Considering altering both the color choices and placements again. 
A way to imagine exact color change placements beginning with solid colors repeats once more, which can be followed by new color separations. 
The existing repeat may be reduced further to 18 X 64, eliminating some of those extra rows in the center of the chevron shape 
The new BW image, tiled: 
Whether or not the design is intended to retain chevron shapes in alternating textures, actions may be plotted pre knitting in any way that visually makes sense to the person designing the pattern and tools available to them. 
Reversing the png so that the more textured stitches will begin with the color in yarn position 1
Using either repeat, color changes now occur after every 32 rows knit. Another color change location clue is in the needle selection change above and immediately following the red border in the chart on the left. 
Adding colors can be planned cautiously or allowed to happen randomly depending on the preferences of the designer and end-use. Ribber fabric designs are not visible until several inches have been knit, too late to catch color sequence errors. Some machines allow for memo placements or sounds to help track color changes, but only within the initially programmed repeats. A quick spreadsheet can provide customizable checkboxes or added information. For an attempt to retain chevron shapes in different textures: 
When using 3 colors, rather than 4, the texture of the zigzags on any specific color, will vary in placement. It is easy to change colors in any chart to approximate those that will actually be used in the knitting. 
Proof of concept: each of my yarns is slightly different in both thickness or fiber content from the others, which can be a drawback in resulting textures. As in any 2 color dbj, if 4 consequent rows are knit in one of two colors the positive and negative portions of the image reverse, as seen at the top of the swatch. The green was not intended to be used originally, the white yarn simply ran out. Such accidents at times may provide pleasant improvements. There is bleed-through of each color behind the other in the tighter knit areas as well which contributes to visual color blending, noticeable even in the areas with fewer tucked stitches. 
Splitting zig-zags into triangles, working color 1 with color 2, followed by color 3 with color 4 pairings 
A PDF including row numbers and space for notations zig zag
An editable Excel spreadsheet created as an export from numbers zig zag
For Mac owners a Numbers doc. zig zag
A simpler repeat suitable punchcard owners as well using only 2 colors 
The test swatch and observations: patterning was begun with color 2, yellow.
The yellow yarn is 12/16, the maroon is 2/15 in thickness.
The triangle, because slip and tuck stitch settings are used, is compressed in height, while there is enough tuck happening to still make the knit wider.
The pattern is 24 stitches wide, the swatch was knit on 40 needles. Smaller swatches are fine for testing tension and colors. If committing to larger pieces, tests on at least 100 stitches by 100 rows are needed for gauge calculations in any double bed work or very textured patterns on the single bed. On some occasions when a far larger number of needles are in use, problems may turn up that require going back to the drawing board in terms of items ie tension settings, weight used, etc.
A: patterning was begun with thicker yarn, the yellow, in color changer position 2, both yarns are 100% wool
B: KCI, end needle selection on, a 2 color “beaded” edge is created
C: KCII, end needle selection canceled, patterning occurs on end needles
D: transferring to the top bed and using the standard latch tool bind off for these fabrics is far too tight 
The tiled repeat, 24X48, does keep the stitch quality constant for both colors, Assumptions based on optics of tiling are not always accurate clues to potential patterning errors, here those darker lines are part of the actual design 
Continuing on a 24 stitch repeat, the original design may be rendered at double height and separated once more, doubling the separation height to 96 rows 
There are days when either or both machine and knitter need a break. At the start of the first swatch, the cam buttons were not set, resulting in plain knit stripes. At its top, the purple did not get picked up properly from the color changer, and the knitting of course fell off the machine. On a second try, the same issue happened again with the purple yarn. Multiple incidences of such events were fondly nicknamed “dropitis” by my students. The test is on 24 stitches, the width of a single repeat, the triangles are much more balanced in size, this knitter is putting this pattern to rest. 
Another try at the diamond shapes that began this topic. The first .png
when tiled appeared to not have enough space between the shapes, was amended to this 
the differences when tiled 
the color separation can happen completely within Gimp using color invert 
the white yarn is an acrylic, slightly thicker than the purple toned one. Sometimes simply exchanging yarn positions can change the qualities of the overall fabric. 
The repeat begins with 2 blank rows. To achieve the tighter white shape as opposed to the honeycomb purple one, at the start of the repeat that color needs to be in use on rows where knit stitches happen as the KC, set on slip to the right, knits needles brought forward to D position. Red in this chart segment marks pertinent rows
Both with hand knits and commercial knits because of the hand actions possible on both sides in the first, and as many as 4 beds selecting and knitting on the other may be in use at the same time with more complex needles as well, there are fabrics that are difficult or even impossible to duplicate. There often are obvious differences in the results, but the journey may still yield results that are pleasing and worth pursuing. 
Another even more complex inspiration from a sweater attributed to Falke, Spring 20 collection, using similar stitch structures, but in addition, also transferring stitches between beds exposing a purl striped ground.
Adding needles out of work by simply choosing to cast on and working on every other needle it does not matter whether even or odd needles are in use, the pattern will be identical but simply shifted over by one needle. For frequent color changes, make the first preselection row toward the color changer to start with, keep notes as to where the repeat color selections happen as experiments are expanded, evaluate color choice as a third or even fourth color are introduced 
the third tuck row on the machine 
the fourth tuck row with needle preselection for the first all knit blue row 
Two from one: the same tuck repeat was altered by changing the needle out of work arrangements. Slub yarn may be used but changes the value of the lines formed by the floats created in the needles out of work gaps. 
Chain cast on 2 in work, 2 out of work, end with 2 needles in work
Number 11 is a close relative but worked on every other needle 
The rayon used in the previous sample, and a 2/8 wool, were less successful than a 2/11 acrylic in knitting the swatch. The stitches need to be as tight as possible while also needing to be able to knit off properly
The same directions apply in this instance, the first sample worked with no needles out of work 
This knit begins on every needle 
Eliminating those ladders or floats, here eyelets are created where stitches are held for two rows. 
push first 2 of needles out to hold 
COL knit 10 rows, bring the third pair of needles into work, knit one row
Shell shapes: #4 and # 20 directions are given in the 2017 blog post 
Some of the trims in this pub may be far more easily and quickly executed using tuck stitches.
For some reason, I found the commands erratic when working on the translated version of the site, and fared much better in the original language publication.
Screengrab the final image surrounded by extra white cells, and open it in GIMP.
Getting a preview of how a finished garment might appear, here the tiled version is 192 pixels in width and one may glean some idea as to whether that repeat should ever really be used in a sweater or even a blanket. Further image scaling or cropping can happen based on the knit gauge. 
A very quick rendering imagining pattern and color placements using a simple sweater outline 
Collections of every other needle repeats for processing with a similar approach may be found in these volumes, available for free download
Both volumes include accompanying swatch illustrations.
For a better, printed match size, after capturing the image from the PDF for a single page outside image edges, opening it in Gimp, and cropping it to content, it is then possible to scale the results to measurements of a factory punchcard equal in width and adjusted for the number of rows in the image. My card required print measurements were 14.1cm by 26.1. Scaling executed with an aspect ratio that is too long. 
breaking the chain-link, removing size constraints 
The results with the selection of even rows simply shift the result up a row 
Test in your version of the program to see whether releasing the shift key prior to making edits changes them. Either way, being consistent in the choice makes for less confusing results. Experimentation takes a matter of seconds.
using the rectangle tool, either odd or even rows may be chosen, remaining consistent for the height of the repeat in a scale to suit the end fabric goal. Here the original file is lengthened X2
working with the original file lengthened x4. The selections can happen on every row or every other, whether singly or in pairs. Note the difference between making the first selection on the first pair of rows or the second. 
2021: 
single click on the filing cabinet icon on the right, 
double click on the patterns folder, and its own window will appear, 
and the new folder will be added within the brushes one 
For future use, any saved brush may be dragged and dropped into the named personal pattern folder icon, or into the folder after it has been expanded or opened in its own window. My opened brush folder 
When exporting self-drawn brushes, the option is offered for adding spacing surrounding the shape, here a 10% addition was chosen 
To save personal patterns, instead of choosing the file cabinet icon in preferences, one may choose the folder icon, following a similar series of steps to those above, including verifying the contents of the newly created folder 
Use Windows, Dockable Dialogues, choose Pattern. The patterns will show on the right
Click on the paint bucket, then on the pattern you wish to use on right, hover over the canvas with the paint tool, click on it and the image will fill in the chosen pattern.
Foreground and Background colors: in RGB Mode, click on the foreground color to select a new color for the grid, click OK 
This command is found in the image menubar through 
You can create as many guides as you like, positioned wherever you like.
Built-in or custom brushes may be superimposed on a bucket-filled ground. Create an image in the desired width and height, here 24 X 24, and magnify at least X 800 for a grid view.
The color exchange window will appear. Here the white “from color” is left undisturbed. Select the dropper next to the “to color”, then click on the image on the color you wish to change, a palette window will appear. Make your choice, the color exchange window will now have substituted the chosen color for black, click OK, and white design areas are now changed to the chosen blue globally. 
The process may then be repeated with the second color if desired. The color exchange window will show white as the default “from color”. Click on the white bar, choose black from the palette window or use the dropper to select black from the image. The from color will then appear as black. Repeat selection with the dropper from the right of the “to color” bar on any black pixels in the image, choose the color from the palette window to replace it, and the color exchange window will display the new “to color”. Click OK, and job done. 
The process may be repeated multiple times on the same design or used on large-scale ones, giving one some idea as to whether or not to really commit to the estimated colors. 
I recently had reason to review old PC files from my Passap knitting days and came across several cut files that when converted to png format appeared in colors rather than black and white, leading me to experiment with color exchange again. The image for the first experiment is part of a crib blanket by Cheryl Giles
It is possible to colorize images originally drawn in black and white. The color exchange options will remain fixed throughout the process. The image may be worked on continuously and exported when color exchanges are completed, or saved and imported again after each step. The color exchange here happens consistently on the chosen background color, changing that quickly becomes familiar and easy. There are times that the repeat being processed will turn black onscreen, trust in the process and continue.
Developing custom palettes in order to visualize different colorways while using the same repeat:
this window will open with selections for possible palette choices 
click on your choice, then click on the palette icon, and your color choices will appear, click on the white, to create a new background color. 
My success with series of other images in using color exchange has been spotty. Online forums reveal this is a recurrent issue with no clear solutions. Suggestions include stipulating that the cause may be the version of Mac OS in use. Color reductions using 
The image itself may be scaled concurrently to tweak grid border alignments. The final grid size below is 18X18, the image size is shown after scaling from a width of 277 pixels (with a broken link at that time) to a final 270 pixels in width 
The screengrab of the above center, with a superimposed new grid; note the image, in this case, was also offset for better placement, a 3-pixel pencil was used to isolate the border of the possible smallest repeat 
Translating the colored image to BW indexed may take several steps and some clean-up if only Gimp is used to process it. With the colored large-scale isolated repeat, the image is opened in Gimp. The Threshold tool transforms the current layer or the selection into a black-and-white image, where white pixels represent the pixels of the image whose Value is in the threshold range, and black pixels represent pixels with Value out of the threshold range. It may be activated from the pull-down colors menu or from the toolbox. 
Color separations: there are occasions where very small repeats need to be scaled in height only for color separations. I have found such scaling to be inaccurate using the option, such as here, both of the small, single repeat, and in scaling its tiled version. The triangle motif was used in many of my early posts on color separations for DBJ and its backing options. 
The appearance of the final repeat when color is reversed 
Another comparison of the 2 options for altering every other pair of rows in the specific color separation for a mosaic repeat. There is less filling in of cells with a different color, but in large files especially, I feel the result would become far more visually confusing to track. 
Working with potential knit repeats the scale is reduced further. Magnification is useful for the evaluation of repeats. The smallest repeat segments for use on electronic machines may be isolated. The filter, map, and tile option easily verify how the repeats line up overall. Cropping a 24-stitch width and tiling that also visualizes the suitability of the repeat for use on punchcards with the 24-stitch limitation. Grid view helps identify any need for “clean up”.
and a type of symmetry and accompanying settings, click on pencil tool, the motif will appear as on the above right, paste the image on the new canvas, undo and repeat setting adjustments until satisfied with the distribution of motifs.
The 24X50 repeat: 
To decrease crowding, using the original image, the new canvas is now 40X60, with the shift decreased from 12 to 8 pixels. The result did not tile properly when mapped, using magnification 800X with a viewed grid the final repeat, 29X60 was isolated 
Being more deliberate with the math leads to a full, successful repeat 
Using that small triangular 8X8 repeat
Again, preemptive math will yield images that avoid further processing. It is up to the user to recognize any problems, the repeat here needs to and can be isolated correctly from the file on the left, it is actually only 16 rows high. Here the adjusted repeat is created on a 24X16 canvas with the same symmetry settings, and filter/mapped/tiled 
The above repeat was cropped and adjusted to 16 stitch width and 8 row height, the file saved, and the process repeated 
Using symmetry once more, remember to adjust the pencil size. 
I was unable to use color exchange successfully on the above images, but with the saved 2 colors indexed red and white repeat both img2track and ayab appeared to load the repeat successfully. 
The map color exchange was successful using the steps described at the top of the post when beginning with the repeat drawn in a black and white version. 
Nearly all my previous dbj pieces have been knit on a Passap E6000. The 930 experience for such repeats is new to me. With some help from Tanya Cunnigham in reviewing the steps required when using img2track, I returned to cellular automata repeat saved years ago.
That provided an opportunity to decide I preferred the reverse color placement as well as wanting a thicker ply for the white, resulting in twice the fun with 2 colors, and another scrapped sample 
I was able to achieve a reasonable repair on the knit side, but the birdseye pattern on the reverse is a bit scrambled. 
There is also potential for exchanging colors to get a sense of how the pattern might appear in different colorways 
Segments marked with green cells may be grouped in a variety of ways to create repeats in different widths, asymmetrical ones are also a possible consideration
The samples below were knit using a 2/8 wool, at T4, are shown folded along their center on the right of the photos, with the open edge on the left as they came off the machine. 
The usual single bed tension for this yarn might be 7 or 8, depending on stitch type. The greater the number of knit stitches on either bed, the closer the tension will have to be adjusted to that used in stocking stitch for the same yarn. Wool also has memory, will want to roll to knit side at the top and bottom, to the purl side along vertical edges, steps often need to be taken to reduce the rolls. Using this repeat 
A variety of edgings may be produced by simply hooking up ladder floats created by leaving needles out of work after X number of rows. In this instance chain cast on over 11 needles, dropping the center 5 chains and taking the corresponding needles out of work.
This variation uses the thicker blue yarn, knit at tension 4; 12 rows are knit before hooking up the lower groups of six ladders, which makes the floats easier to pick up or count using a single eye tool. Repeating selection on the same side allows the trim to be easily bent around corners 
Trims using holding alone border on the possibility of automation using slip stitch programming. A simple one to start: cast on 7 stitches, with the center needle out of work. Knit a few rows, set knit carriage to hold.
translated for knitting, patterning may be used on either bed, with the opposite bed set to knit every stitch. If patterning is on the ribber, have the first and last needles in work on the main bed. 
The top bed is set to tuck in both directions, the fabric is shown lightly stretched 
and could conceivably be used to create a ruffled edge when followed by narrower stitch types ie. every needle rib or Milano variants 
Changing settings: with the knit carriage set to slip in one direction, knit in the other, the ribber knitting every row
Needles may be taken out of work to create pleats in every needle ribs, alternating their placement between the 2 beds. Knit stitches stabilize tuck ones. Here every other needle is taken out of work on only one bed. The tuck loops are more visible in any open spaces between the vertical rows of ribbed stitches. The ribber will knit every row on the same needles aligning directly above each other, thus ruling out full pitch.
The needles are set up so that the first and last are in use on the ribber, ensuring that a knit stitch will be on the side of any tuck stitch selected on the top bed, 
on the top bed the every other needle tuck selection reverses as the direction of the knit carriage does, needles brought forward knit, the ones skipped hold tuck loops in their needle hooks, 
the resulting fabric 
Choosing spacing between needles in work on the main bed 
A working repeat with 4 circular rows, 6 full rows knit 
My first swatch in the technique was in response to a Ravelry member share describing the stitch pattern used in a finished garment 
followed by float formation when only the top bed knits 
The resulting grid may be used as a guide for hand techniques off the machine in isolated areas or all over 
Needle arrangements may be varied to accommodate thicker yarns, or alter the texture by varying both the number of knit rows and circular ones 
Because the top bed needles are in pairs, the EON selection remains evident, each of the first 2 passes completes one row of knitting.
When only the top bed knits, floats are formed between the needles in work 
Half Milano with tucked long stitch: the main bed needles will tuck one row, then slip one row. The ribber needles will first knit a row, then slip a row while the second bed knits both rows. Then the ribber needles knit one row then slip a row while the second bed knits two rows. 
I have had no success with trying to execute my interpretation of the directions without getting floats on the top bed, and the photo in Machine Knitter’s Guide to Creating Fabrics is not clear enough to distinguish if there indeed are floats on the surface of the fabric. The experimental repeat 
the tuck row is formed with the knit pass to the right, no preselection 
the row of stitches is skipped on the way to the left, preselecting for the next first knit row, tuck loops visible on top of the hooks of the selected needles 
the process is repeated. The resulting fabric: 
In DIY the potential for exploration is endless. As always, if needles are out of work on the main bed, end needle selection is canceled. Here slip setting in both directions is used, along with needles out of work on both beds, the 1X1 needle repeat is programmed.
the result has floats on the purl side, a slightly pleated look on the knit side. 
After both no preselection row bring alternate needles out to hold using any EON needle tool. In my case, COL, I began with needle 1 on the left on row 3, alternating beginning with needle 2 on the left on row 6. The number of rows in between hand techs is an odd one, so sides for the hand tech will alter as well. This shows the tuck loops formed EON as the carriages travel to the right.
Prior to resuming pattern knitting, needles with loops on them need to be returned to the B position, maintaining the EON needle preselection for the next pass 
Repeat the process when design row 6 is reached, beginning with needle 2 on the left. The texture appears on the purl side of the piece, shown on the left
This repeat uses 6 passes as well. The tuck loops on the top bed occur above slipped stitches in the previous pass, which may be replicated, but the real problem is that every third row on the ribber is also having to tuck on specific needles with no knit stitches between them. The tuck loops happen directly above knit stitches formed in the previous row if the tucking lever is changed manually from R to P on those rows. That is a lot to juggle, a no. 
Here the eon tuck would fall on slipped stitches in the previous pass, so that is doable. It is possible to fool the lili selection into believing there are extra needles in work on each side of the ribber, which can “make” the first stitch on either side knit rather than slip or tuck. The method is used in creating a 
This pattern repeat is a short one, the changes are more regular on the ribber. The hand tech tuck stitches could be formed for 2 rows with all stitches getting worked back to B position in between those preselected for the next pattern row. The lili buttons need to get fooled after alternating pairs of rows, the start of several nos for me.
This is from a Japanese language manual for the 891(1987-89) punchcard machine, which appears to introduce the idea of replacing the use of the knit carriage and plaiting feeder with one specifically designed for intarsia 
Planning for interlock:
when the lili buttons are used with the machine set to slip in both directions. Studio or Knitmaster knitters would require an RJ1 ribber carriage. I refer to the marks on the Brother ribber needle tape as blanks and dashes. When lili buttons are in use, one must work on an even number of needles. Pairs of both are required. The starting placement on either of the 2 marks does not matter, the first needle on the carriage side on the left will always slip, with the last stitch away from the carriage always being knit. This observable if one “air knits”, slowly moving the ribber carriage from side to side. As in any pattern knitting, needles selected to D or E will knit, the ones lined up in B position will slip or tuck. 
Imagining the sequences required to complete a single row of knitting. I prefer to start with a knit stitch on the left, top bed, end needle selection is canceled 
When testing new ideas, particularly in rib setups, I often begin on a small number of needles and in a way that feels “safe”. This was my first test, with the ribber set at half-pitch. There is an obvious difference in rib before the slip stitch segment and the every-needle, EN, segment. 
Using a very thin space-dyed cotton, tension 4 on both beds, produced a soft, drapey, squishy fabric. Because once the cast on and needle set up are complete, the knitting occurs on every other needle in alternate directions, full-pitch is used without any problem even though every needle is in use on both beds. 
after only the top bed knits with slip stitch floats behind every skipped stitch, which, in turn, will appear longer on the knit face
Ponte di Roma
the modified version of the repeat used in my test swatch
Pairs of rows of interlock are followed by pairs of circular rows. The repeat was changed and the second color was used to define the difference in stitch formation between the two groups, color changes were made every four rows. 
Using a single pair of carriages and having to constantly change cam settings appears far too complicated to manage for producing any length of fabric. My hack for making things easier and faster was to resort to knitting with 4 carriages. One pair was set for interlock operating from the left, the other set so as to achieve tubular knit. The ribber carriage is set to knit from right to left and to slip from left to right when the main bed knits. The knit carriage is set to slip in both directions so that the pattern selection remains continuous. It will slip all stitches while moving to the left on rows with no needle preselection, knit on all preselected needles on its return to the right.
My initial test was to knit twice as wide a repeat, thinking it might be easier to identify stitch formation, working on 4 X an odd number of stitches, in this case, 36, beginning and ending with knitting on the top bed, 
single row pockets are formed. 
With both part buttons pushed in, in every needle rib, the needles in D will knit, the ones in B get skipped completely. As the carriage passes to the right, the needles for the next row are preselected, come forward holding only the skipped stitches in the row just knit, while the alternate needles are set up to be skipped on the next pass to the left 
After the two passes one full row of knitting is completed on the patterning bed. The needle preselection is now on the next row of the repeat, in this case, row 1.
The process repeats throughout. Two passes complete a single row of knitting. The carriage actions for completed passes 1 and 2 
The close-up begins to make the tuck loops a bit more visible. The swatch was knit at half-pitch. Using full pitch in patterns that allow for it, diminishes the appearance of “ladders” between rows of stitches, indicated by cyan arrows. 
Manually the tucking lever position can be changed from R to P for a single row or more of tucks and then returned to the R placement. Switching between the 2 stitch types on the ribber is far easier and less complicated than changing cam buttons on the main bed, however, there are no rows where only tucked loops are created without knit stitches beside each of them if the lili buttons are in use. Using the slip-tuck Brother selection on the main bed allows for slip and tuck settings to be used at the same time in the same row as long as opposite cam buttons are in use. Some of the old punchcard books include patterns referred to as “lace-like” using the setting. The starting side makes a difference in results as to whether one leads with a slip stitch float or a tuck loop in the actual knitting. Swatches in this post have begun with the first needle in work on the ribber and a forward, to be knit, stitch selection on the first needle on the top bed, with an even number in work on both beds. The end needle selection is canceled unless stated otherwise. The cam setting used for these tests 
After the return pass to the left, the tuck loops are evident on top of the needles preselected forward to knitting position on the next pass to the right. Two carriage passes fill one row of knitting, here ending COL. 
On the ribber, as seen in the thumbnails, one may choose slip or tuck in one direction alternating with an all knit row in the other, or tuck or slip in both directions in an alternating pattern EON_EOR, on an even number of needles with the addition of lili buttons. The appearance on the ribber of the formation of the loops echoes that seen on the main bed changing needle placement unless the carriage is set to tuck in only one direction. 
A test can quickly be made to observe the stitch formation with the main bed set to knit every row. I chose the left tucking lever down to R when the carriages were on the left, up to P when the carriages reached the right. The tuck stitches with no further action line up over the knit stitches in the previous row 
Experiments outside the interlock family: the two-by-two repeat is supplied in most packets of cards that come with the purchase of a punchcard machine. At one point in time, Kate Armitage published a book containing 104 variations of knitting using the card, both single bed and combined with ribber use. There was also the equivalent for card #3, the point being variations are limited only by time and imagination. 
