How to knit P3tog tbl – purl three together through the back loop

A step by step tutorial showing you the p3tog tbl knitting stitch – a right-leaning decrease for the purl side

I begin with the assumption that nobody could convince you to avoid this most complicated knitting decrease of them all. To be fair, it’s the only way to achieve a right-leaning decrease when knitting the wrong side of stockinette stitch or garter stitch in the round. So, here’s how to knit the p3tog tbl purl decrease.

P3tog tbl is the abbreviation for purl three together through the back loop. This double decrease is quite similar to p2tog tbl but considerably more difficult to knit. From the right side, it will look like a right-slanting k3tog or a bit like an SSK. The left-leaning counterpart is the standard p3tog, and there”s also a centered purl double decrease.

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Reading tip: If this is too difficult, here’s how to decrease knitting stitches for beginners.

Two alternative ways to knit a left-leaning double purl decrease

Now, I already mentioned that this is a very difficult decrease which I personally would avoid as much as possible. That being said, there is a somewhat easier way to achieve a left-slanting double purl decrease. Or I wouldn’t even call it easier but a bit more consistent to knit if that makes any sense.

I found two versions, and I think alternative a) is probably much easier

A) Purl, Slip, Pass-Over twice (PSPSSO2)

I really like this version and I would recommend it as the standard version:

• Step 1: Purl one stitch through the back loop
• Step 2: Slip it back to the left needle (without twisting; just needle tip to needle tip)
• Step 3: Pass the second stitch over the one you just slipped (a bit like a bind-off)
• Step 4: Pass the third stitch over as well
• Step 5: Slip the remaining stitch back to the right needle purlwise

B) Slip, Twist, P3tog

This is another version I found but it really is a pain to knit, so I’m not sure how much easier it really is. It work but that’s about it.

Step 1: Slip three stitches purlwise one at a time to the right needle without knitting

Step 2: Insert your right needle into all three stitches at the same time from right to left (this will feel quite awkward) and slip them back to the left needle as one unit.

Step 3: Purl these three stitches together the regular way.

This will result in the very same decrease, though the slipping back and forth is quite a bit awkward if there are a lot of these decreases in a pattern. But at least it’s a bit more reliable than trying to wiggle through your needle through the back loop all the time.

At the end of the day, you should always check if you can’t substitute a p3tog tbl with easier stitches. Either by decreasing from the knit side or by knitting two single-decreases next to each other (for most lace patterns, the latter wouldn’t be an option, though!)

Reading tip: The ultimate list of knitting decreases – centered, right-, and left-leaning alternatives for every project.

And that’s how to p3tog tbl. Feel free to comment below in case you have any questions