Have you ever seen the instruction ktbl or k2tog-tbl and wonder what, exactly “tbl” means? Ktbl stands for “knit through back loop.” Just as “pick up” and “pick up and knit” are somewhat confusing terminology, “knit through the back loop” can also be confusing, because each knit stitch has only one loop on the needle. So what exactly does this abbreviation mean?
Ktbl actually means to knit a stitch through the back of the loop, that is, to knit through the leg of the stitch that is sitting behind the needle.
Here’s an extreme closeup of a standard knit stitch. Pick up some of your own knitting and insert the needle into the stitch to knit. See how you are putting the needle into the part of the stitch that is sitting in front of the left needle? Look at the photo below and notice how this opens up the stitch. When you look at the finished piece of knitting (there’s a swatch below), notice how the little knit stitches look like rows of Vs.
Now, here’s an extreme close up of knitting “through the back loop” aka “ktbl”. See how the right needle is inserted into the part of the stitch that is behind the left needle? Look closely at the stitch and notice how it is different than the stitch above. Instead of being opened up, the legs of the stitch are being crossed, creating an X at the bottom of the stitch. If you look at the swatch below, you can see how each of the stitches makes a small X instead of a V. Recently when I was teaching a knitting class in Alaska, one of the students gave me a great way to remember this stitch. She said, “You can tell when a stitch has been knitted through the back loop, because the stitch looks like it has to go potty.” I bet you’ll never forget that now!
So, why would you ever want to knit a stitch through the back loop and twist it? I use this technique in ribbing to create a more structured and tidy looking ribbing. I usually knit ribbing too loose and my stitches look sloppy. But when I twist the stitches in the ribbing, the pattern is much neater.
Top: Standard Stockinette stitch
Bottom: Twisted Stockinette stitch
Bottom: Twisted k1, p1 ribbing (*ktbl, p1; rep from *)
The differences between these swatches looks subtle, but the texture and flexibility of the fabric can change drastically when a lot of stitches are twisted.
Some knitters cross their stitches without realizing that they are knitting in an unusual fashion. There are times when you want to knit twisted stitches intentionally, but it can create undesirable results when you are twisting stitches by accident. Twisted stitches are tighter than standard stitches, and they create a fabric that is stiffer than plain knitting. This can ruin the drape of a sweater and it can also prevent a piece of knitting from felting. Felting requires loose stitches that move around during agitation, and if you’ve knitted a piece with twisted stitches, you may find that it does not felt to the desired size, and that the felted fabric shows up the shape of the stitches, even after prolonged agitation in a washing machine.