Ptbl: purl through the back loop (twisted purl)
Ptbl means purl through the back loop. It twists a purl stitch and is used in twisted rib worked flat. How to work it, with tips for Continental knitting.
By Julia WallinCo-founder and editorPtbl means purl through the back loop. You purl into the back of the stitch instead of the front, which twists the stitch at the base. It is the purl version of ktbl.
How to work ptbl
Keep the yarn in front, as for a normal purl stitch.
Bring the right needle behind the work. Insert it into the back loop of the stitch from left to right.
The right needle now crosses behind the left needle, with the tip pointing towards you. Angle the tip back towards the normal purl position.
Wrap the yarn as for a normal purl.
Pull the new loop through to the back and let the old stitch slide off the left needle.
Tips for Continental knitting
With the yarn in your left hand, ptbl is harder than a normal purl. Three things help:
Do not work too tightly. Tight stitches are harder to get into on the next row.
Push the wrapped yarn through with your left middle finger.
Give the finished stitch a small tug so it settles.
When to use it
Patterns use ptbl mostly in twisted rib worked flat. You work k1tbl on the right side and p1tbl on the wrong side, so the columns stay evenly twisted. Ptbl is also used in fully twisted rib in the round (k1tbl, p1tbl) and in twisted-stitch patterns. In the round, many patterns skip ptbl and twist only the knit stitches (k1tbl, p1).
Some shortcut methods for a twisted purl twist the stitch in the opposite direction to a true ptbl. That looks even in a piece worked in the round, but it shows if you mix it with flat sections worked with true ptbl.
Common mistakes
Splitting the yarn. The angle is awkward, so use needles with sharp tips and go in slowly.
Going in from the wrong direction. The stitch then turns round on the needle instead of twisting.
Frequently asked questions
What does ptbl mean in knitting?
Purl through the back loop. You purl into the back of the stitch, which twists it. It is the purl version of ktbl.
Why is ptbl so hard?
On a purl row the back loop faces away from you. The needle has to go behind the work and point back towards you before you can wrap the yarn.
Do I need ptbl for twisted rib?
Only for fully twisted rib, or for twisted rib worked flat, where you need it on the wrong-side rows. The k1tbl, p1 version in the round needs no ptbl.
What does ptbl look like from the right side?
Like a twisted knit stitch, with an X at the base instead of a V. That is why it keeps twisted columns unbroken when you work flat.
Co-founder and editor at knyt. Knits every guide before it is published.
