It's very common to decrease by using a knit two together (K2Tog), but there is another stitch you should know: 'knit two together through the back loop' (K2Tog TBL). This stitch is essentially the same decrease, but it adds a little twist to the pattern and it can also be used to correct stitches after a mistake.
How to Work K2Tog TBL
To perform this decrease, you work the same as if you were knitting through the back loop of just one stitch, but instead, you go through two.
- Your right-hand needle goes through the back loop of the first stitch, then the second.
- Make a knit stitch as normal, pulling both loops off the left-hand needle.
- One stitch remains on the right-hand needle.
A 'purl two together through the back loop' (P2Tog TBL) stitch is exactly the opposite. It is most often used to decrease and twist on purl rows.
Tip: The abbreviation TBL is used to indicate 'through the back loop.' Most patterns use this abbreviation in either lower or upper case. You might also see it written as 'in the back of the stitch' or with a '-b' added to the stitch. For example, K2Tog-b or K1-b.
What Does a K2Tog TBL Do?
The most common reason to use a K2Tog TBL is to twist the knit stitch while decreasing. It's the same purpose as a single knit stitch through the back loop and creates a nice texture in the finished fabric.
You might use the K2Tog TBL if you want to decrease and shape a pattern worked in something like the Twisted Stockinette stitch.
Use the Back Loop to Untwist Dropped Stitches
Just like other back loop stitches, you can also use the K2Tog TBL while correcting a mistake. Let's pretend - though it's often reality - that you had to frog your knitting past a row with a K2Tog stitch.
While you're putting the stitches back on the needle, they get twisted.
Rather than fumble and attempt to straighten them out, you can K2Tog TBL through a decrease and it will automatically untwist the stitch.
More Common Decrease Stitches
It's very true that you will use the K2Tog TBL in very rare instances. Most knitting patterns will use one of these decrease stitches instead, so you will find them to be more valuable in your projects.
- SSK (Slip, Slip, Knit) - The opposite of a K2Tog, this stitch slants to the left rather than the right. In very rare occasions, you may be asked to knit it through the back loops as well (SSK TBL).
- P2Tog (Purl Two Together) - Often worked on the purl row of a pattern, this is a very common decrease and it's easy to do.