What an SSK is and why you use it

An SSK (slip, slip, knit) is a left-leaning decrease that removes one stitch from your needle. You slip two stitches one at a time, then knit them together through the back loop. The result leans to the left on your finished fabric, which makes it useful for shaping — especially on the left side of a garment where you want decreases to mirror a right-leaning decrease (called a K2tog) on the opposite side.

SSK appears in nearly every knitting pattern that involves shaping: armholes, necklines, sleeve caps, and raglan decreases. Learning it means you can follow patterns as written instead of substituting a different decrease and ending up with uneven shaping.

Key Takeaways

  • An SSK is performed by slipping two stitches individually, then knitting them together through the back loop in one motion.
  • The decrease leans left on your fabric, making it the mirror image of a K2tog (knit two together) decrease that leans right.
  • You work an SSK on a knit row; on a purl row, use the equivalent PSP (purl, slip, purl) instead.
  • The stitch count after an SSK is one less than before — two stitches become one.

The step-by-step motion

Hold your working yarn in the back (as if you were about to knit). Insert your right needle into the first stitch on your left needle from left to right, as if you were going to knit it. Slip that stitch onto your right needle without knitting it — your right needle now holds one slipped stitch.

Repeat: insert your right needle into the next stitch on your left needle from left to right and slip it onto your right needle. You now have two slipped stitches on your right needle, sitting side by side.

Insert your left needle into the front of both slipped stitches (the left needle goes in from left to right, through both loops at once). Knit these two stitches together by wrapping your yarn and pulling through. You have now decreased by one stitch — two stitches have become one.

Common mistakes and how to avoid them

The most frequent error is slipping the stitches with the yarn in front instead of the back. If your yarn is in front when you slip, the slipped stitches will twist and your decrease will look uneven. Always check that your working yarn is in back before you begin.

Another mistake is knitting through the front of the slipped stitches instead of the back. If you knit them normally (front loop), the decrease will lean right instead of left, and you have just made a K2tog by accident. The "through the back loop" part is what creates the left lean. Slow down and make sure your left needle enters from the front of the stitches, going through the back loops.

Some knitters slip the stitches knitwise (the way you would knit them) instead of purlwise (the way you would purl them). Slipping knitwise twists the stitch slightly. Slip purlwise — insert your needle as if you were about to purl, then slip without wrapping yarn. This keeps the stitch untwisted.

When to use SSK versus other decreases

Use SSK on the left side of your work when you want a left-leaning decrease. On the right side, use K2tog (knit two together), which leans right. Together, they create balanced, symmetrical shaping — for example, one SSK on each side of a neckline opening will frame it evenly.

If your pattern calls for a centered decrease (one that does not lean either direction), use a different stitch like a centered double decrease (CDD) or slip 2 together, knit 1, pass slipped stitches over (SK2P). But if the pattern specifically says "SSK", use it — the designer chose it for a reason.

On a purl row, the equivalent of an SSK is a PSP (purl, slip, purl). The motion is the same, but you work from the purl side instead of the knit side, and the decrease still leans left on the finished fabric.

Practicing the motion until it feels natural

Cast on 15 stitches in a worsted-weight yarn on size 8 or 9 needles. Knit a few rows in garter stitch (knit every row). On the next row, knit 5 stitches, then work an SSK, then knit the remaining stitches to the end of the row. Knit the next row plain. Repeat this pattern — SSK on every other row — until you reach the end of your practice swatch.

As you work, pay attention to the motion becoming automatic. Your fingers should learn the rhythm: slip, slip, knit through the back loop. After a few practice rows, you will stop thinking about each step and your hands will know where to go. This is the point at which SSK stops feeling clumsy and becomes part of your regular knitting.

Reading your fabric to check if you did it right

After you finish a row with an SSK, look at the decrease on the knit side of your fabric. A correct SSK leans noticeably to the left — the two stitches that became one should angle in that direction. If it leans right, you knitted through the front loop instead of the back. If it looks twisted or uneven, you may have slipped knitwise instead of purlwise.

Compare your SSK to a K2tog decrease on the same swatch (knit two together leans right). Holding them side by side, you should see that they are mirror images. If they look the same, one of them is wrong. Use this visual check to catch mistakes early, while you still remember what you did.

Frequently Asked Questions

What is the difference between SSK and K2tog?

Both remove one stitch, but they lean in opposite directions. K2tog (knit two together) leans right; SSK leans left. They are mirror images, which is why patterns use both to create balanced shaping on either side of a neckline or armhole.

Can I use SSK on a purl row?

Not directly. On a purl row, use PSP (purl, slip, purl) instead. The motion is the same, but worked from the purl side. The decrease still leans left on the finished fabric.

What if I slip the stitches knitwise instead of purlwise?

The stitch will twist slightly, and your decrease may look uneven or distorted. Always slip purlwise — insert your needle as if you were about to purl, then slip without wrapping yarn. This keeps the stitch in its normal position.

Does the yarn weight matter when practicing SSK?

Thicker yarn makes the motion easier to see and control. Start with worsted weight or bulky yarn on larger needles (size 8 or 9). Once the motion feels natural, you can use SSK with any yarn weight.

What if my pattern says "slip 1, knit 1, pass slipped stitch over" instead of SSK?

That is a different decrease called SK1P or PSSO. It also leans left, but the motion is slightly different — you slip one, knit one, then pass the slipped stitch over the knit stitch. Both work, but follow what your pattern asks for.