What a PSSO is and when to use it

A PSSO — pulled slip stitch over — is a decrease that removes one stitch from your needle by slipping a stitch, knitting the next stitch, then pulling the slipped stitch over the knit stitch. It looks nearly identical to a standard slip-slip-knit (SSK) decrease, but uses a different hand motion to get there. Both decrease one stitch and slant the same direction on your finished fabric.

You'll see PSSO called for in patterns that want a left-leaning decrease, often paired with a knit-two-together (K2tog) on the opposite side of a garment to create symmetrical shaping. It appears most often in lace patterns, fitted sweaters, and anywhere the pattern designer wants the decreases to be visually balanced.

The main reason to choose PSSO over SSK is hand comfort. If your hands tire easily or you find slipping two stitches one at a time awkward, PSSO uses a simpler slip motion and may feel smoother in your rhythm.

Key Takeaways

  • PSSO stands for pulled slip stitch over and is a left-leaning decrease that removes one stitch from your needle.
  • The three steps are: slip one stitch knitwise, knit the next stitch, then pull the slipped stitch over the knit stitch using your left needle.
  • PSSO and SSK create the same look on finished fabric but use different hand motions to get there.
  • Practice the pull-over motion on a practice swatch before using PSSO in a pattern, because the tension of that final step affects how your decreases look.

Step-by-step: How to work a PSSO

Step 1: Slip one stitch knitwise. Insert your right needle through the next stitch on your left needle from left to right, as if you were going to knit it. Slide that stitch onto your right needle without working it. You now have one slipped stitch on your right needle.

Step 2: Knit the next stitch. Knit the following stitch on your left needle in your normal way. You now have two stitches on your right needle: the slipped stitch and the new knit stitch.

Step 3: Pull the slipped stitch over. Use the tip of your left needle to lift the slipped stitch (the one closer to your needle tip) up and over the knit stitch, then let it drop off your right needle. You have now decreased by one stitch. One stitch remains on your right needle.

Common mistakes and how to avoid them

The most frequent error is slipping the stitch purlwise instead of knitwise. When you slip purlwise, the stitch twists on your needle and the final decrease looks uneven or loose. Always insert your right needle from left to right, the same direction you would knit.

The second common problem is pulling the slipped stitch over too loosely or too tightly. If you yank hard, the stitch below it gets distorted and your fabric puckers. If you barely lift it, the stitch sits awkwardly and creates a visible gap. The motion should be firm but smooth — lift the stitch cleanly over the knit stitch and let gravity help it fall off your needle.

A third mistake is working PSSO when your pattern calls for SSK. They look the same on finished fabric, but if your pattern specifies one or the other, the designer tested that specific decrease in that specific spot. Stick with what the pattern says unless you have a physical reason not to.

PSSO versus SSK: Which decrease to use

Both PSSO and SSK are left-leaning decreases that remove one stitch. On your finished fabric, they look nearly identical. The difference is purely in how your hands move to create them.

SSK requires you to slip two stitches one at a time, then insert your left needle through both and knit them together. PSSO requires you to slip one stitch, knit one stitch, then pull the slipped stitch over. If your hands cramp during SSK or you find the double slip confusing, PSSO may feel more natural.

If a pattern specifies one decrease, use that one. If a pattern says "left-leaning decrease" and leaves the choice to you, either works. Many knitters keep both in their toolkit and switch based on what feels comfortable in the moment.

Practicing PSSO on a swatch

Before you work PSSO in an actual project, spend 10 to 15 minutes on a practice swatch. Cast on 15 stitches in a worsted-weight yarn and knit 4 rows in garter stitch (knit every row). This gives you a stable base.

On row 5, knit 3 stitches, then work a PSSO using the next two stitches. Knit to the end of the row. Knit row 6 normally. Repeat this pattern for 8 to 10 rows so you work PSSO multiple times. This repetition trains your hands to find the right tension and rhythm.

Look at your decreases from the front of the swatch. They should form a neat diagonal line slanting to the left. If they look loose, bunched, or uneven, adjust your tension on the pull-over step. Once your decreases look consistent, you're ready to use PSSO in a pattern.

Reading your pattern to know when to use PSSO

Patterns write PSSO in different ways. You might see "PSSO", "P1 SSO" (purl one, slip stitch over — an older term), or sometimes just "sl 1, k1, psso" written out in full. Check your pattern's abbreviation key at the start to be sure.

In lace patterns, PSSO often appears in pairs with K2tog on opposite sides of a central stitch or motif. This creates balanced shaping that looks intentional rather than accidental. If you see PSSO on the right side of a decrease pair and K2tog on the left, that's the pattern designer creating symmetry.

Some patterns use PSSO in the same row multiple times. Work each one in sequence, and remember that each PSSO removes one stitch, so your stitch count drops by one for each decrease you work.

Frequently Asked Questions

Is PSSO the same as SSK?

They create the same look on finished fabric and both lean left, but they use different hand motions. PSSO slips one stitch, knits one, then pulls the slipped stitch over. SSK slips two stitches and knits them together. If your pattern specifies one, use that one. If it just says "left-leaning decrease," either works.

What if I slip the stitch purlwise by accident?

Your decrease will look twisted or loose because the stitch is now oriented differently on your needle. Slip knitwise (left to right) every time. If you catch the mistake before moving to the next row, you can tink back and redo it. If you notice it later, you can usually live with it, but practicing on a swatch first prevents this.

Can I use PSSO on every decrease in my pattern?

You can use PSSO wherever a left-leaning decrease is called for. However, if your pattern specifies K2tog, SSK, or another decrease by name, use that one. Pattern designers test specific decreases in specific spots for a reason — the fabric behaves differently depending on which decrease you choose.

My PSSO decreases look loose compared to the rest of my knitting. What's wrong?

The most likely cause is tension on the pull-over step. If you're pulling too hard, you distort the stitch below. If you're barely lifting the slipped stitch, it sits loose on your needle. Practice lifting the slipped stitch firmly but smoothly over the knit stitch, then let it fall naturally. A practice swatch helps you dial in the right feel.

Do I need to block my knitting differently if I use PSSO?

No. PSSO decreases block and behave the same way as SSK or any other left-leaning decrease. Blocking won't change how your decreases look — that's set by your tension during knitting. If your decreases look uneven before blocking, they'll still look uneven after.