Purl through the back loop (ptbl) looks similar to a regular purl stitch, but upon close inspection you will notice that the “legs” of the stitch are crossed.
Purl through the back loop is a twisted stitch that adds a decorative effect to your work. It also creates a slightly tighter stitch than a regular purl stitch, though it’s not usually used over a wide area because it tends to bias (slant) the fabric.
The back of a ptbl looks just like a knit through the back loop (ktbl), and vice versa.
The term “purl through the back loop” is a bit of a misnomer. It would be more correctly stated as “purl through the back of the loop”.
Watch this video to learn how to ptbl in both the Continental style and English style.
How to Purl through the Back Loop
- Bring your yarn forward between the needles (just like you do for a purl stitch)
- Insert your right needle through the back of the 1st stitch from below the stitch, bringing your right needle tip in front of the left needle
- Wrap the yarn counter clockwise around the right needle and pull it through the stitch (this is just like doing a regular purl)
- Slide the stitch off your left needle
Now look at your ptbl. If you stretch your work from side to side, you will notice that your ptbl shrinks, rather than expands like a regular purl stitch. This is because purling the stitch through the back loop twists it, making the left and right “legs” of the stitch cross. The arrows in the photos below point to the columns of ktbl & ptbl stitches.
The back of a ptbl looks just like a ktbl. Therefore, it might be a little easier to see the difference between ptbl and a regular purl stitch by looking at them on the knit side of the fabric.
Want to Practice Ptbl?
Ptbl and ktbl are used in the beautiful Idril sweater to help accentuate and tighten the neckline edge. The lessons in our Idril Knit Along guide you step-by-step through the pattern. Check it out at https://knitalongclub.com/course/idril/.