What PSSO Means and When You Use It

PSSO stands for "pass slipped stitch over," and it is a decrease that removes one stitch from your needle. You slip a stitch without knitting it, knit the next stitch, then pull the slipped stitch over the knitted stitch and off the needle. The result is one fewer stitch on your needle, and the decrease leans to the left on your finished fabric.

PSSO appears in patterns when you need to shape your work — narrowing a sleeve, tapering a neckline, or creating a decorative decrease line. It pairs with other decreases like K2tog (knit two together) to create balanced shaping on both sides of a garment. You will see it written in patterns as "sl 1, k1, psso" or sometimes abbreviated as "ssk" (slip, slip, knit), which is a similar but slightly different technique.

Key Takeaways

  • PSSO is a left-leaning decrease made by slipping a stitch, knitting the next stitch, then passing the slipped stitch over the knitted one.
  • The stitch must be slipped knitwise (as if to knit) to keep it in the correct orientation before you pass it over.
  • PSSO decreases one stitch per row and is often used on the left side of a garment to balance right-leaning decreases like K2tog.
  • The most common mistake is slipping the stitch purlwise, which twists it and creates an uneven-looking decrease.

Step-by-Step Instructions for PSSO

Step 1: Slip the first stitch. Insert your right needle into the next stitch on your left needle as if you were going to knit it (knitwise). Slide that stitch onto your right needle without knitting it. The stitch should sit on your right needle in the same orientation it had on the left needle.

Step 2: Knit the next stitch. Knit the following stitch on your left needle normally. You now have two stitches on your right needle — the slipped stitch and the newly knitted stitch.

Step 3: Pass the slipped stitch over. Use the tip of your left needle to lift the slipped stitch (the one closer to the tip of your right needle) and pull it up and over the knitted stitch. Let it drop off the right needle. You have now decreased by one stitch.

The whole motion takes about three seconds once you have done it a few times. The key is keeping the slipped stitch loose enough that it lifts easily, but not so loose that it unravels. A gentle tension on your working yarn as you knit the second stitch helps.

Common Mistakes and How to Avoid Them

The most frequent error is slipping the stitch purlwise instead of knitwise. When you slip purlwise, you insert the needle from right to left (as if to purl), which twists the stitch. When you pass it over, the twisted stitch creates a bumpy, uneven-looking decrease. Always insert your needle knitwise — from left to right — even though you are not actually knitting the stitch.

Another mistake is pulling the slipped stitch too tight as you pass it over. If you yank it, the stitch below it can stretch and create a hole or loose spot in your fabric. Lift the slipped stitch gently and let gravity help it slide over the knitted stitch. A light touch produces a neater decrease.

Some knitters also forget to slip the stitch at all and straightforward knit two stitches together, which creates a K2tog instead of PSSO. These are different decreases with different leans, so if your pattern calls for PSSO on one side and K2tog on the other, mixing them up will throw off your shaping. Read the pattern abbreviation carefully before you start the row.

PSSO vs. SSK: Which Decrease to Use

PSSO and SSK (slip, slip, knit) both create a left-leaning decrease, but they are made slightly differently. With PSSO, you slip one stitch, knit one, then pass the slipped stitch over. With SSK, you slip two stitches knitwise one at a time, then insert your left needle into the front of both slipped stitches and knit them together.

Many modern patterns call for SSK instead of PSSO because SSK is easier to execute consistently and produces a slightly neater edge. However, both decreases lean the same direction and work the same way in a pattern. If your pattern calls for PSSO and you prefer SSK, you can substitute it without changing how your garment looks. The choice comes down to which motion feels more natural in your hands.

Using PSSO for Balanced Shaping

Shaping looks best when decreases lean away from the center of your work. On the right side of a neckline or armhole, use K2tog (which leans right). On the left side, use PSSO or SSK (which lean left). This creates a symmetrical V-shape that frames your neck or shoulder.

If you decrease on both sides of the same row, work the right-side decrease first, then continue across the row, then work the left-side decrease near the end. This keeps your stitch count even and your shaping centered. Many patterns will say something like "decrease 1 stitch each side every other row" — that means one K2tog on the right side and one PSSO on the left side, worked on alternating rows.

Practicing PSSO on a Swatch

Before you work PSSO into a garment, practice it on a small swatch using worsted-weight yarn and size 8 or 9 needles. Cast on 20 stitches and knit 10 rows in garter stitch (knit every row). On row 11, knit 5 stitches, then work PSSO, knit to the end. Repeat this decrease every other row until you have only 10 stitches left.

Look at the column of decreases you created. The stitches should form a neat diagonal line leaning to the left, with no twists or holes. If your decreases look bumpy or uneven, check that you are slipping knitwise and not pulling too tight as you pass the stitch over. A few practice rows will train your hands to find the right tension and rhythm.

Frequently Asked Questions

What is the difference between PSSO and K2tog?

PSSO leans left; K2tog leans right. PSSO is made by slipping a stitch, knitting the next stitch, then passing the slipped stitch over. K2tog is made by knitting two stitches together as one. Both decrease by one stitch, but they create opposite slants in your fabric.

Can I use PSSO on every row?

Yes, you can decrease every row if your pattern calls for it, though most patterns ask for decreases every other row or every third row to keep shaping gradual. Decreasing every row creates a steeper slope and is common near necklines or armholes where you need to remove many stitches quickly.

What does it mean if my PSSO looks twisted?

A twisted PSSO usually means you slipped the stitch purlwise instead of knitwise. The stitch rotated as it went onto your needle, and when you passed it over, the twist stayed in the fabric. On your next swatch, insert your needle from left to right (knitwise) when you slip, even though you do not knit the stitch.

Do I need to use PSSO if my pattern says SSK?

No. SSK and PSSO create the same left-leaning decrease and are interchangeable in patterns. If you find SSK easier or more comfortable, substitute it without changing your results. Both techniques produce the same shaping and appearance.