What SSK Does and Why You Use It

SSK (slip, slip, knit) is a left-leaning decrease that removes one stitch from your needle while tilting the fabric to the left. You slip two stitches one at a time, then knit them together through the back loop. It pairs with the right-leaning knit-two-together (K2tog) decrease to create balanced shaping on both sides of a garment — think the edges of a sleeve cap or the sides of a fitted sweater.

The reason to learn SSK instead of just using K2tog everywhere is that SSK and K2tog lean in opposite directions. When you decrease on both sides of a neckline or armhole, using SSK on the left side and K2tog on the right side makes the decreases mirror each other visually. Without that balance, one side looks like it's leaning away from the edge while the other leans toward it.

SSK is also gentler on yarn than some other decreases. Because you're slipping the stitches first, you're not pulling the working yarn as hard as you would with a K2tog, so the stitch sits more evenly in the fabric.

Key Takeaways

  • SSK is performed by slipping two stitches knitwise one at a time, then knitting them together through the back loop in a single motion.
  • The decrease leans left, making it the mirror image of a knit-two-together decrease that leans right.
  • You'll see SSK written in patterns as "SSK" or sometimes "sl 1, sl 1, k2tog tbl" in older or very detailed patterns.
  • Practice the motion slowly on a swatch before working it into a garment so the tension stays even with the rest of your stitches.

The Step-by-Step Motion

Start with your working yarn in the back of your work, as if you're about to knit a stitch. Insert your right needle through the first stitch on your left needle from left to right (knitwise), and slip it onto your right needle without knitting it. The stitch moves over but stays unworked.

Repeat that motion with the second stitch: insert your right needle knitwise through the new first stitch on your left needle, and slip it onto your right needle. Now you have two slipped stitches sitting on your right needle, and they are twisted — the leading leg of each stitch is at the back of the needle instead of the front.

Insert your left needle through both slipped stitches from left to right, going through the back loop of each one. This is the part that feels awkward at first — you're going the "wrong" direction through stitches that are already on your right needle. Knit these two stitches together as one stitch. You now have one new stitch on your right needle, and two stitches have become one.

Common Mistakes and How to Fix Them

The most frequent error is slipping the stitches purlwise instead of knitwise. If you insert your needle from right to left (purlwise), the stitches don't twist the way they need to, and your decrease will lean the wrong direction or look sloppy. Always insert knitwise — left to right — even though you're not actually knitting the stitch.

Another common mistake is knitting the two stitches together through the front loop instead of the back loop. If you do this, you've created a right-leaning decrease instead of a left-leaning one, which defeats the purpose. The back loop is the one farther away from you when you're looking at your needles. Angle your left needle so you can see clearly which loop you're going through.

Tension problems often show up as one stitch being much looser than the others around it. This usually means you pulled the working yarn too hard after completing the decrease. The new stitch should be snug but not strangled. If it's loose, tighten it gently on your next row by pulling the working yarn a little firmer as you work the stitch next to it.

Practicing SSK on a Swatch

Before you work SSK into a real project, spend 10 to 15 minutes on a practice swatch. Cast on 20 stitches in a worsted-weight yarn and a size you're comfortable with — US 8 or 9 needles work well for learning. Knit 6 rows in stockinette stitch (knit on the right side, purl on the wrong side).

On row 7, knit 5 stitches, then work SSK, knit to the end. On row 8, purl across. Repeat rows 7 and 8 until you have only 10 stitches left. You should see a clear left-leaning line of decreases running down the middle of your swatch. If the line looks uneven or leans the wrong way, unravel back to where it went wrong and try again. This is exactly what practice swatches are for.

Once the motion feels natural and your decreases look even, you're ready to use SSK in a pattern. Keep the swatch — you can compare your tension and stitch appearance to it later if you're unsure whether you're doing it right in a garment.

SSK in Different Stitch Patterns

In stockinette stitch, SSK sits cleanly and the left lean is obvious. In ribbed patterns, you may need to adjust when you work the decrease so it doesn't interrupt the rib. If your pattern calls for SSK at the edge of a ribbed section, work it inside the rib (not on a knit column) so the visual line of the decrease doesn't cut across the vertical lines of the rib.

In textured stitches like seed stitch or moss stitch, SSK works the same way technically, but it may be less visible because the texture already breaks up the fabric. The decrease still removes a stitch and still leans left — it's just less dramatic to look at. This is fine and expected.

In lace patterns, SSK is often paired with yarn overs to create intentional holes and shaping at the same time. The decrease removes a stitch while the yarn over adds one, keeping your stitch count stable. Follow your pattern exactly for placement, because the visual effect depends on where the SSK and yarn over sit relative to each other.

SSK Versus Other Left-Leaning Decreases

SSK is the most common left-leaning decrease, but it's not the only one. Skp (slip, knit, pass slipped stitch over) is another option — you slip one stitch, knit one, then pass the slipped stitch over the knit stitch. Skp creates the same left lean as SSK, but some knitters find it harder on the yarn because of the passing-over motion.

Sl2tog-k1-psso (slip 2 stitches together, knit 1, pass slipped stitches over) is a double decrease that removes two stitches at once and leans left. You'd use this when a pattern calls for a more dramatic shaping, like at the top of a hat crown or in a lace motif. It's not a substitute for SSK in most patterns — it's a different tool for a different job.

For most everyday knitting, SSK and K2tog are all you need. Learn both, and you can handle nearly any shaping a pattern throws at you.

Frequently Asked Questions

What's the difference between SSK and K2tog?

K2tog (knit two together) is a right-leaning decrease where you knit two stitches together as one without slipping them first. SSK is a left-leaning decrease because you slip the stitches first, which twists them and changes the direction the decrease leans. They're mirror images of each other.

Can I use SSK on every decrease in a pattern?

Technically yes, but your shaping won't look balanced. If you use SSK on both sides of a neckline, both decreases lean the same direction, which looks off-center. Use SSK on one side and K2tog on the other for symmetrical shaping.

Why does my SSK look loose compared to the stitches around it?

You're probably pulling the working yarn too hard after the decrease, or the tension in the stitch before the SSK is too loose. Work the stitch after the decrease with slightly firmer tension, and make sure the stitch before the SSK isn't already loose. Even tension across the whole row prevents this.

Do I slip the stitches knitwise or purlwise?

Always slip knitwise (left to right), even though you're not knitting the stitch. Slipping purlwise twists the stitches the wrong way and your decrease will lean right instead of left or look distorted.

Can I use SSK in circular knitting?

Yes, SSK works exactly the same way in the round as it does flat. Use it on the right side of your work (the outside of the garment) for decreases that lean left, and pair it with K2tog on the left side of your work for balanced shaping.