Geometric shapes on ribber fabrics with tuck stitches

The previous post elicited a facebook query as to whether it might be possible to create solid shapes within the field of brioche vertical stripes. The inspiration for the query was a hand knit pattern published in ravelry 

https://www.ravelry.com/patterns/library/pariss-brioche-scarf 

Many terms are used in instruction manuals and published directions. In my notes I will refer to fabric with tucking on both beds as  full fisherman rib, tucking on one bed only as half fisherman.  These were my first attempts at exploring the inspiration idea, the fabric has inherent differences as it requires both slip and tuck stitch settings, so technically it is neither fisherman. Knitting happened on a random drop stitch day, which explains the patterning interruption errors. When attempting to knit isolated geometric areas on a field of frequently tucking stitches, automating the task when possible makes the process easier and faster. This was my first “diamond” pattern repeat, suitable for a punchcard machine as well. The design is illustrated on the left, converted to punched holes/black squares/pixels on the rightThe knit carriage is set to tuck throughout. The programmed repeat will alternate the knit/ tuck functions across the bed based on black squares, punched holes, or pixels. For full fisherman rib (top swatch) the ribber needs to tuck in one direction only, opposite to the action taking place on the main bed. A choice needs to be made on either of these 2 setting directions based on needle selection on the main bed, and stays fixed throughout knitting.  The ribber is set to knit on even numbered design rows on the card, to tuck on odd. Row count numbers may be different than design row ones depending on row counter settings by the operator or built KM ones. Below are tuck settings for to the right on top, to the left on the bottom.

For half fisherman rib (middle swatch), the ribber is set to knit with every pass.

Note the half fisherman fabric is narrower than the full. Also, I am not used to my 930, overlooked that the machine was set for isolation, so its bottom diamond shaped repeats are incomplete. 

In the bottom swatch I tried to produce a more distinct shape on tubular tuck created with only knit stitches on both sides of the fabric. Hand selection on the alternate beds on all tuck rows produced knit stitches in the desired area. A needle out of work made it easy for me to find proper location on needle bed .

Getting back to automating at least part of the process for such shapes: the repeat needs to be alteredThe main bed will be knitting the black squares in the chart on the right on every row, tucking the white ones. When the ribber carriage is on the side appropriate for it to tuck the following row and no needles are selected in design segments on the top bed (odd numbered design rows, ones with majority of black squares, tuck <— —>  may not be used in those locations because then the resulting stitches would be tucking on both beds with nothing holding the tuck loops down. 

bring all needles between selected main bed needles up to hold on the ribber so that they will knit while the remaining needles tuck on the next pass of the carriages. 

In my sampling the ribber was set to tuck when moving from right to left. Below is the resulting swatch, shown on both sides. Part of one diamond shape is missing due to the fact I was concentrating on moving needles around and missed the change in selection on one side of the machine.Back to the original the method used in the previous post where ribber settings are changed from knit to tuck <– –> every 2 rows along with color changes. I chose a design that would  make it easy to identify location of non selected needles on the main bed on rows where ribber will be set to tuck in both directions. The result is interesting, but the “solid” areas, narrower than the remaining knit, are in the opposite color to the dominant one on each side, the reverse of the inspiration fabric.
When needles are not selected on the main bed, interrupting the every needle selection bring all needles on the ribber between selected needles up to hold on each of the 2 passes from left to right, and right to left. Stitches on those needles will knit rather than tuckresulting in this fabric The first swatch at the top of this post was achieved going a very different route. Two knit carriages were used to select and knit from opposite sides of the machine. Each carried one of the two colors. When working with the first color and  coupled carriages  the main bed is  set to tuck <– –>, and the ribber to knit <– –>. The second color is knit using the main bed knit carriage only, set to slip <– –>.  A knit sinker plate may be altered  and  used on knit on main bed only rows, adjustments to it are shown in post http://alessandrina.com/2018/04/15/ribber-fabrics-produced-with-2-knit-carriages-selecting-needles/. The chart for my working repeat with a multiple of 4 rows in each pattern segment, color changes every 2 rows indicated on rightIn trying to produce a diamond shape using this technique, my first repeat had arbitrarily placed pixels: the cam settings on the right of the swatch images correspond to those used in each swatch segment. Colors were changed every 2 rows throughout. First 2 rows in pattern were knit in tuck setting, followed by 2 rows knit in slip. In segment B when no needles were selected on the top bed, all those needles were brought out to hold before knitting to the opposite side. Because every row is now knitting in corresponding color changes the result is a striped pattern. Segment C is knit with both carriages set for 2 rows as in C1 alternating with knit carriage only set as in C2.  At that point the color being carried knits only on the ribber, skipping non selected needles on the top bed, avoiding the striped result. A float is created between the beds in areas where no needles are selected that will be “hidden” as one returns to knitting in rib with 2 carriages.  The arrow in the chart points to an area where two colors were picked up with the color swap rather than one. The resulting swatch samples 

Analyzing the result in section C: the diamond is the same color on both sides, whereas the initial rectangular shape experiment reverses the colors. Reworking the diamond repeat in segments that are each a multiple of 4 rows:Other considerations in DIY designs. The background repeat for this pattern is actually composed of units 2 wide by 4 rows high. If the pattern is intended to be repeated across a larger number of stitches on the machine bed than that in the chart, it is always worth tiling the image to pick up any errors (sometimes happy design features).  Tiling in width readily shows the error, tiling in height as well proofs row intersections as welltiling the corrected width repeat, now 42 stitches wide by 72 rows highI sometimes tend not to keep immediate notes when I test ideas, which often comes with a price. I knit my first swatch using this repeat beginning the pattern with 2 rows of tuck, resulting in this fabric (and some randomly dropped stitches once more) with the same color diamond on both sides:Beginning the pattern with 2 rows of slip stitch on the main bed only mirrors the swatch at the start of this post. Where no needles are selected on the main bed, with passes of the combined carriages, two rows of tuck will now be produced, resulting in the wider geometric shapes and the increased bleed throughThe tuck loops created by the white in this instance have the elongated slip stitches in the alternate color (blue) partially covering them, creating the darker geometric shape in the top detail photo. The blue is thinner than the white, the effect will vary depending on yarn weight and tension used for the main bed yarn. One can begin to observe the change in width in areas with more stitches tucking. 

If the aim is to have a tighter, more clearly defined diamond, after the swatches rested, the swatch that began in slip stitch setting appeared to “work” better to my eye, even with the single color geometric shape on both sides taken into account. Ultimately the choice is a personal one.  The wider vertical stripes created in the white yarn in the slip combination fabric happen because of the 2 stitch wide repeat on the top bed as opposed to a single needle one in a true fisherman knit. Because of the slip setting the results will be narrower in width from it as well.

Ayab knitters will need to program any repeat across the width of the intended number of stitches, and use the single setting. Electronic knitters can enlarge the background pattern field easily, or create brickwork, extended repeats.

Arah-paint offers a free program that allows drawing repeats in different orientations with a few mouse clicks. Shifting the this pattern must also be in pairs of pixels/black squares in this instance because of the 2X4 stitch background unit. The 21 (half) pixel shift shows an error in its continuity a 22 stitch shift results in a “correct” all over repeat 

Reversible DBJ, Brother knitting machines

I am including notes on my working through the process and some of my stumbles at the start of this post. More specific how tos  are found toward the bottom of it.

Such fabrics may be created with both the KRC built in function, or with the color separations that knit each color for each design row for 2 consecutive, identical rows. Punchcard knitters are not excluded. The starting side is on the left for the KRC setting (B in this illustration), on the right side for the alternate color separation (C, double length or drawn with each row repeating X 2). I am still testing my 930, for my samples I began by using the built in pattern #16 in the Stitchworld Pattern Book I.In the absence of a jac40 the fabrics are knit by manually selecting stitches to upper working position (E on Brother) on the ribber bed every row. Preselection for the next row to be knit on the main bed makes the process far easier. 

In my first sample, the colors are the same on each face. Since the same number of needles are selected for both design and ground, both sides of the fabric will be exactly alike. There will be floats, enclosed by knit stitches of the opposite color. Beds are set at half pitch. Consistency makes any process easier and more predictable. My ribber set up was also with an extra needle on the ribber at either end of those in work on the main bed. I found I had less issue with the long floats in my design when I made certain the needle selection began with needles to the left of those in work on the opposite bed rather than to the right, allowing for the color in use to knit first on the ribber, then in turn on the main bed. It may not matter with patterns with shorter spans worked between the 2 colors. The dropped stitch issues below were resolved by using different yarns, no other changes. 
The needle set up in colored squares and on my needle beds showing matching selections on both beds (different design rows). Some of the floats may be seen created by the blue yarn in the bottom photo. If first and last needle on each side were not selected on the main bed, the needles at each end on the ribber were added to hand selections for next row (blue squares)


better results with the different yarn choice

For DBJ that reverses ground and pattern colors, opposite needles are selected on each bed. Color 1 knits the design on one bed and the background on the other at the same time, while color 2 knits the reverse. There are no floats. I knit this fabric as well at half pitch. The ground color created pockets (white squares), with the pattern color (black squares) locking the layers of fabric together. Here again, first and last needles on the ribber were worked on each row. I began pushing needles up on the ribber beginning to the right of each needle in work on the main bed. Needle selection on ribber matches unselected needles on main bed (pink). All needle positions each bed are mirrored. 

needles actually selected on both beds (pink), different design row One design row, 2 different angles

Since ribber fabrics are not visible for a large number of rows, I frequently scrap off after short distances to proof technique before committing to longer pieces as well as to asses whether the effort is worth it in order to produce the fabric in that particular technique or yarn.

Moving on to a self drawn pattern, the technique proved to be sound. On inspection however, I saw I was actually missing a pixel in the .bmp I downloaded, and on the reverse the green arrow is most likely operator error in needle selection. The orange dots highlight the missing pixel/contrast color stitch, and on the color changer side I had a really sloppy edge that needs sorting out (red dots).  A possible added factor: I knit the motif using KCI, and later recalled end needle selection does not always work with the carriage I am using. Here I filled in the missing pixel, and drew a single pixel black line along each side, testing a “border”. The first and last needles on each side were now cast on and in work on the main bed. 

That single stitch solid color line does not add to the design in my opinion, so back to the drawing board: side “border” pixels are eliminated. The first and last stitch are now in work on the ribber. This fabric is the best by far, at the very start I forgot to cancel end needle selection (KCI), then switched to canceling it, KCII on electronic. The how to in summary: first and last needle are on the ribber. On the electronic choose KRC for the built in color separation for the fabric to be worked in DBJ. KCII (no end needle selection). With free pass to right, both carriages set to slip <– –>,  select for first row of knitting to be worked in color represented by white squares in the design chart. Both carriages remain set to slip in both directions throughout. On the ribber bed, bring up to E/hold position first needle on the right of any needle selected on the top bed, then continue to push needles up into work to match the number of not selected needles on the knit bed.  As needles are arranged, there will be a space between the last hand selected needle on the ribber, and the next needle in work on the main bed Now that there is that extra needle in work on the ribber on the color changer side, to match selection as seen above, needles are hand selected to E beginning on the far left, still keeping that space just before the next needle selected by the pattern reader. Remaining selections began to right of needles on main bed as described above.when selection begins on the main bed on the left Getting back to working the same pattern on both sides of the knit: first needle on the left is on the ribber, the one on the far right on the main bed. On the electronic select KRC for the fabric to be worked in DBJ. KCII. With free pass to right, both carriages set to slip <– –>,  select for first row of knitting to be worked in color represented by white squares in the design chart. Both carriages remain set to slip in both directions throughout. On the ribber bed, bring up to E/hold position first needle on the left of any needle selected on the top bed, then continue to push needles up into work to match the number of selected needles on the knit bed.  Small selection errors are seen on left image, ie on the second row on its right, may be easily repaired by duplicate stitching. The stitching yarn may be fed easily through layers of double knit for short distances before and after the “mistake”. With all settings and yarn being equal, there is a difference in size between this fabric (larger of the 2) and the one with color reverse on its other side 

A similar set up, working in full pitch. Here needles line up directly below each other. If wrong needle is selected it will be point to point with the needle immediately above it, and is an added clue the wrong needle is being pushed up into hold/ E position. My first swatch had distinctly different side / vertical edges. Cast on was for every needle, half pitch (top image), first needle on left on main bed, last needle on right on ribber. When completed, it was  followed by change to full pitch prior to pattern knitting, lining up needles point to point, directly below each other (bottom image).  I prefer the edge obtained on the half pitch throughout, seen in previous  sample 

Still pondering those edges, and what about repeats with large areas of solid color? The image on the left is 25X26 rows in height, the one on the right adjusted for an even number of solid color rows, and a total row repeat divisible by 4, 25X28. The single black line at the top is a marker for returning the carriage to all knit when the top of the repeat is reached. When using full pitch, solid areas remained open at both edges with carriage set to KCII. A wooden tool handle is actually inserted through from one side to the other in the bottom of the swatch. Because the needles are point to point, no extra needles could be brought to work on both ends as a work around. KCI will select end needles on main bed. I tried that as the first work around to seal the edges. I paid no attention to whether needles were selected at each end every row, and got another creative pair of edges. 

Returning to half pitch I brought up to work the first needle on the left every row (too many rows at seen at R top edge compared to other side) and pushed the last needle on right up to work if it was not part of the group to be brought up to E. Analyzing the fabric structure in those areas of solid colors on alternating beds: at first full pitch makes sense if one has knit tubular stripes or solids which have closed edges, with the yarn making a single pass on each bed, traveling back to the color changer, with the option to stripe every X, even number of rows. Such stripes occur evenly spaced and identical on both fabric sides. Here the goal is to knit the fabric with large blocks of solid, alternate colors on each side. The main bed knits color 1 on selected needles on the top bed only, the alternate color is knit with the ribber needles being hand selected up to E while the main bed is slipping, with none of its needles selected. Other than that first set up row with preselection from the left, 2 rows are knit in color A, followed by 2 rows in color B. There are no stitches traveling between the beds to seal the fabric together in those areas, creating open sides, so if the goal is to have the edges seal. other steps need to be taken. A single pixel solid line along either edge of the repeat did not create a good edge. Full pitch is easier than half pitch to manage. One possible solution to both issues is to alter the side edges of the design repeat so there will be alternating needle selection along those side edges, thus sealing the fabric. 

I decided to cast on with white, and to continue with white as the first color used in pattern (white squares in chart). This swatch was knit in full pitch. Edges are sealed throughout. The only hitch was when the top was reached and that all black squares row was reached. I was on the right at that point, with my dark color in the feeder. The row toward the left would have knit in the dark color instead of the white on the top bed.  I cut the dark yarn, made a free pass to the left, continued in plain knit in white to right, and then transferred stitches and bound off. Top and bottom edges /borders in terms of number of rows, whether to add pattern there as well, are all subject to personal preferences and taste.

For an off topic reversible double bed fabric using thread lace setting, see post