SSP and P2tbl: Advanced Purl Decreases + Easy Alternative

Originally published on March 15, 2025

Not all left-leaning purl decreases are created the same way, but in the end, they will look identical, no matter how you knit them. While the SSP (Slip, Slip, Purl) is slightly cleaner than the p2tbl (purl 2 together through the back loop), both create a left-leaning decrease that mirrors the right-leaning p2tog (purl 2 together).

An SSP is a single decrease technique typically worked on the purl side of the fabric (also known as the reverse stockinette stitch side). On the right side of the fabric, it creates a left-leaning decrease that mirrors the SSK (Slip, Slip, Knit). 

In this post, you’ll learn:

• What SSP is and how to work it

• What p2tbl is and how to work it

• When to use SSP and p2tbl

• An easy alternative to SSP

• Key tips for knitting purl decreases

SSP (Slip Slip Purl through the back loop)

What is SSP?

SSP stands for "Slip, Slip, Purl." It’s a decrease that creates a left-leaning slant when viewed from the knit side of the fabric. SSP is often used in projects where symmetry is important, such as mirrored decreases on either side of a garment.

How to Work SSP

SSP involves a few extra steps compared to p2tog, but the result is a clean, professional-looking decrease. Here’s how to do it:

1. Slip the first stitch knitwise: Insert your right needle into the first stitch as if to knit and slip it onto the right needle. This reorients the stitch.
2. Slip the second stitch knitwise
3. Return the stitches purlwise back to the left needle: Without disturbing their new orientation, place both stitches back on the left needle.
4. Purl through the back loops: Insert the right needle into the back loops of both stitches (from back to front) and purl them together.
   

This creates a decrease where the second stitch is pulled over the first stitch, resulting in a left leaning decrease.

Insert your right needle into the first stitch as if to knit and slip it onto the right needle	Slip the second stitch knitwise	Return the stitches purlwise back to the left needle

Insert the right needle into the back loops of both stitches (from back to front)	It should look like this	Purl both stitches  together

The decrease from the back...	...and from the knit side

What is P2tbl?

P2tbl stands for "purl 2 together through the back loop". Like SSP, it creates a left-leaning decrease, but it skips the reorientation steps. This makes it faster to knit, but it doesn’t look as neat as SSP on the knit side of the fabric.

How to Work P2tbl

Here’s how to work the p2tbl:

1. Insert the right needle into the back loops of the first two stitches on the left needle.
2. Wrap the working yarn around the right needle.
3. Pull the yarn through both stitches, creating one new stitch on the right needle.
4. Slip the two stitches off the left needle.

While p2tbl is simpler than SSP (because it skips slipping the stitches knitwise), it doesn’t look as polished on the knit side. However, when working on reverse stockinette stitch, the difference is negligible.

Insert the right needle into the back loops...	...of the first two stitches on the left needle	Wrap the working yarn around the right needle and pull the yarn through both stitches

Slip the two stitches off the left needle.	How it looks from the knit side

When to Use SSP and p2tbl

• SSP: Use SSP when you need a clean, left-leaning decrease on the knit side of the fabric. It’s ideal for projects where the knit side is visible and symmetry is important.
• p2tbl: Use p2tbl when the purl side is the visible side (e.g., reverse stockinette stitch).

Why Choose the Easy SSP?

The traditional SSP can be tricky for some knitters, as it involves slipping stitches, repositioning them, and purling through the back loops. The Easy SSP simplifies this process while delivering the same results. It’s a game-changer for those who find the standard SSP challenging.

How to Work the Easy SSP

1. Slip the stitches: Slip the first stitch as if to knit.
2. Slip the second stitch as if to knit.
3. Reposition the stitches: Insert the left needle into the first and second slipped stitches on the right needle as if to knit.
4. Slide both slipped stitches back onto the left needle.
5. Purl the stitches together: Purl the two stitches together as you would for a standard purl decrease.
   
   

Slip the first and the second stitch as if to knit.	Insert the left needle into the first and second slipped stitches...	...on the right needle as if to knit

Slide both slipped stitches back onto the left needle	Insert your right needle into both stitches purlwise...	...and purl both stitches together

The decrease from the purlside...	...and from the knitside

Why Use the Easy SSP?

• Simplicity: The Easy SSP eliminates the need to twist your stitches or reposition your needles awkwardly.
• Efficiency: It’s faster and more intuitive than the traditional SSP.
• Clean Results: The Easy SSP produces a tidy, left-leaning decrease that looks really clean

Key Tips for Purl Decreases

• Take your time with SSP: The reorientation steps can feel awkward at first, but they’re essential for achieving a clean decrease.
• Experiment with p2tbl: If you’re in a hurry or working on a less visible part of your project, p2tbl can be a quicker alternative to SSP.
• Check your slants: Always double-check the direction of your decreases to ensure they match your pattern’s requirements.
• Reverse stockinette considerations: If your decreases will only be visible on the purl side (e.g., in reverse stockinette), the direction of the slant doesn’t matter as much. In these cases, you can opt for the simpler p2tog for convenience.
• Use sharp needles: I mention this in every blog post, but  sharp-pointed needles make it so much easier to insert your needles into tight stitches, especially when working decreases.

Conclusion

SSP and p2tbl are advanced purl decreases that can be a bit tricky, especially when you only started out with knitting. While SSP offers a cleaner finish, p2tbl is a faster alternative. With the easy alternative, you can avoid knitting through the back loop and the result will still be a left leaning decrese. Practice all three of them and see which one you like most! 

Until then, happy knitting!

A Little Way to Say Thanks