What SSK Does and Why You Need It

SSK stands for "slip, slip, knit," and it is a left-leaning decrease that removes one stitch from your needle while slanting the fabric to the left. When a pattern says "SSK," it means you slip two stitches one at a time, then knit them together through the back loop. The result looks like a mirror image of a regular knit two together (K2tog), which leans right. Most patterns use SSK on the left side of a piece and K2tog on the right side to create balanced, symmetrical shaping.

You will encounter SSK in nearly every shaping project—sweaters, hats, socks, and cardigans all use it to taper sleeves, crown decreases, and necklines. Learning this one technique opens up most intermediate patterns. The motion feels awkward at first, but it becomes automatic after a few rows of practice.

Key Takeaways

  • SSK is a three-step motion: slip one stitch knitwise, slip a second stitch knitwise, then knit both stitches together through the back loop.
  • The stitch leans left on your fabric, making it the mirror image of K2tog, which leans right.
  • You perform SSK on the left edge of shaping to balance the appearance with K2tog on the right edge.
  • Practice the motion on a swatch before working it into a real project so your tension stays even.

Step-by-Step: How to Work an SSK

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

Step 2: Slip the second stitch knitwise the same way. Insert your right needle through the next stitch on your left needle from left to right and slide it onto your right needle. You now have two slipped stitches sitting on your right needle, and they are sitting in the same direction.

Step 3: Knit both stitches together through the back loop. Insert your left needle through both slipped stitches from left to right (going through the back of the loops, not the front). Wrap your yarn and knit them together as one stitch. You have now decreased by one stitch and created a left-leaning decrease.

The whole motion takes about three seconds once your hands know the path. The key is keeping your tension even—do not pull the yarn too tight when you knit the two stitches together, or the fabric will pucker.

Common Mistakes and How to Avoid Them

The most frequent error is slipping the stitches purlwise instead of knitwise. When you slip purlwise, the stitch rotates on your needle, and when you knit through the back loop, you end up twisting the stitch. The result looks uneven and bumpy. Always slip knitwise—insert your needle from left to right, the same direction you would knit.

A second mistake is knitting through the front of the loops instead of the back. If you knit normally (through the front), you lose the left-leaning effect and the stitch sits flat instead of slanting. The pattern will look wrong, especially if you are using SSK to shape a neckline or sleeve cap. Slow down on step 3 and make sure your left needle goes through the back of both loops.

Tension problems also show up quickly. If you pull too hard when you knit the two stitches together, that stitch will be noticeably tighter than the stitches around it. If you pull too loose, the decrease will look sloppy. Aim for the same tension you use for regular knit stitches, and the fabric will blend in.

When to Use SSK in Your Patterns

SSK appears in patterns wherever the designer wants a left-leaning decrease. On a raglan sleeve cap, you will see SSK near the beginning of the row (the left edge) and K2tog near the end of the row (the right edge). This creates a V-shape that looks intentional and balanced. If both decreases leaned the same direction, the shaping would look lopsided.

In a top-down hat, SSK decreases appear on the left side of each crown wedge, and K2tog decreases appear on the right side. The same principle applies: balanced, symmetrical shaping. Some patterns also use SSK in lace or textured stitches where the direction of the decrease matters for the overall design.

If a pattern does not specify which decrease to use, you can usually choose either SSK or K2tog as long as you are consistent. But following the pattern's instructions will give you the exact look the designer intended.

Practicing SSK on a Swatch Before Your Project

Before you work SSK into a sweater or hat, spend 10 to 15 minutes practicing on a small swatch. Cast on 20 stitches in the same yarn and needle size you plan to use for your project. Knit 4 rows in stockinette stitch (knit one row, purl one row, repeat). On row 5, knit 5 stitches, then work an SSK, knit to the end. Repeat this decrease every other row for 6 to 8 rows.

Look at your swatch from the front. The decreases should form a neat diagonal line leaning to the left, and the stitches should be the same size as the rest of the fabric. If the decreases look twisted, bunched, or uneven, go back and check your slip direction and your back-loop insertion. Once your swatch looks clean, you are ready to use SSK in a real pattern.

SSK Versus K2tog: Which One to Use

SSK and K2tog both decrease by one stitch, but they lean in opposite directions. K2tog leans right because you knit two stitches together without slipping them first. SSK leans left because you slip the stitches before knitting them together. In most patterns, you will use both decreases in the same row or round to create balanced shaping.

Some knitters find K2tog easier because it is faster—you skip the slipping steps. But SSK is worth learning because it gives you control over the direction of your decreases, and that control makes your finished pieces look polished. If a pattern calls for SSK and you use K2tog instead, the shaping will still work, but the fabric will not look exactly as the designer intended.

Frequently Asked Questions

What is the difference between slipping knitwise and purlwise?

Slipping knitwise means inserting your needle from left to right, the same direction you would knit. Slipping purlwise means inserting your needle from right to left, the same direction you would purl. For SSK, you must slip knitwise, or the stitch will rotate and your decrease will look twisted.

Can I use SSK on circular needles?

Yes. SSK works the same way on circular needles as it does on straight needles. The motion does not change, and the stitch leans left just as it does in flat knitting. Many patterns use SSK in the round for hat crowns and raglan sleeves.

What do I do if I mess up an SSK a few rows back?

If the mistake is only one or two rows down, you can drop the stitch and use a crochet hook to pick it back up and fix it. If it is further down, you may need to tink (knit backwards) or frog (rip out) back to that row. For now, focus on getting the motion right going forward, and you will rarely need to fix it.

Does SSK work with all yarn weights?

Yes. SSK works with fingering weight, worsted weight, bulky weight, and everything in between. The motion stays the same. With thicker yarns, the stitch may be slightly harder to see, but the left lean will still be there.

Is there a faster way to do a left-leaning decrease?

Yes—slip one stitch knitwise, knit one, then pass the slipped stitch over (psso). This is called SKP and is slightly faster than SSK because you skip one slip step. Both create a left-leaning decrease, and most patterns treat them as interchangeable.