Last week I had a post covering the concept of grafting knitting. Be sure to read that here first!
So, grafting the bind off edge to the cast on edge is the most ideal situation, because it maintains the direction of knitting and produces NO half-stitch offset of stitches.
You need one extra loop on the top (back) needle than you have on the front needle. Every space between two loops on that back needle are what make one stitch – so we’re looking at the spaces between loops – and to have the right number of spaces, we need an extra loop to create that last space.
When you pick up the live loops from the provisional cast on edge, the tail on the back needle gets looped around the needle and then threaded into the selvedge edge to secure that last loop. Like this:
When working with stockinette stitch, our setup for this graft is:
Front Needle – insert as if to purl and leave on. Back Needle — insert as if to purl and drop off, then insert into next stitch as if to knit and leave on.
*FN: insert as if to knit and drop, insert as if to purl in next st and leave on.
BN: insert as if to purl and drop, then insert as if to knit in next st and leave on.*
Repeat from * to * until one st on each needle remains. Drop st on back needle. Insert as if to knit on front needle and drop.
Here is a charted/diagrammed representation. Each back needle loop is two halves – the left-hand base of the stitch on the right, and the right-hand base of the stitch on the left.
(The right letter in a block is the “on” step, the left letter in a block is the “off” step. We work from right to left.)
To get stitches to be the same vertically across the graft, the knit steps should be stacked on top of the knit steps, and vice versa.
When working with something other than stockinette (assuming the pattern is continued vertically), the steps will be a bit different. But you will still work a setup start with [FN: work and leave on. BN: work and drop, then work next st and leave on.] How you work those stitches will change depending on what stitches need to result with the graft.
Here is a video showing this type of grafting working something a bit more complicated than stockinette:
The sample used in the video above is not 2×2 ribbing, but here would be a diagram of the process for 2×2 ribbing:
When working a typical BO to CO graft, there are only 2 possible combinations for the back needle (after the setup):
If you want the base of the stitch above to be a knit – you will work a “Purl off, then knit and leave on”.
If you want the base of the stitch above to be a purl – you will work a “Knit off, then purl and leave on.”
(My “same off, opposite on” rule applies here – with two loops being the base of one stitch on the back needle.)
You will end up working as your “on” step the opposite of what you worked for the “off” step on the back needle.
The front needle can have 4 possible combinations, however, since the “off, on” steps are transitioning BETWEEN two stitches:
Knit followed by a knit. (Knit off, purl on.)
Knit followed by a purl. (Knit off, knit on.)
Purl followed by a purl. (Purl off, knit on.)
Purl followed by a knit. (Purl off, purl on.)
(Again, my “same off, opposite on” still holds true here as well, when you consider the two loops used in the steps on the front needle are two distinct stitches. )
Notice the steps are again stacked on top of each other – a knit step is above a knit step, and vice versa. This is what maintains the same stitches on top of one another vertically across the graft. If you have a stitch pattern that changes from row to row (garter, for example, or seed stitch) – then this DOES NOT apply. I’ll have a post looking specifically at garter tomorrow and at seed stitch on Friday.
I know this can be pretty confusing. Let me know if any of this made things more clear, or if I just confused you more! If you cast on some stitches onto two separate needles and play around with grafting them, it might help to make more sense. (Sometimes working it yourself can help to make things click!)
Until next time, Happy Knitting!