Decreases Shape Your Knitting
Every time a pattern tells you to remove stitches — shaping a neckline, narrowing a sleeve, working the crown of a hat, forming the toe of a sock — it is using a decrease. Like increases, decreases are not interchangeable: each method has a directional lean, a visual character, and an appropriate context. Using the wrong decrease in a visible shaping line is the kind of small error that experienced knitters notice immediately.
Understanding the four main decrease types — k2tog, ssk, k3tog, and cdd — gives you the technical vocabulary to execute any pattern correctly and the judgment to make good choices when a pattern is vague.
K2tog: Right-Leaning Single Decrease
K2tog (knit two together) is the simplest and most common decrease. You insert the right needle tip through two stitches simultaneously — both on the left needle, the first stitch and the one behind it — and knit them as if they were one stitch. One stitch disappears; the remaining stitch leans to the right.
The right-leaning direction is visible: the stitch created by k2tog has its right leg in front and leans toward the right side of the fabric. On a diagonal shaping line, this lean follows the line of the shaping — which is why k2tog is used on the right side of symmetric shaping pairs.
K2tog is tight and tidy. The tension is usually consistent with the surrounding fabric because the two stitches share their yarn cleanly. It is also fast: insert, knit, move on.
SSK: Left-Leaning Single Decrease
SSK (slip slip knit) is the mirror of k2tog. It produces a left-leaning decrease used on the left side of symmetric shaping pairs.
The method:
- Slip the next stitch knitwise (as if to knit) from the left needle to the right needle.
- Slip the following stitch knitwise from the left to the right needle.
- Insert the left needle tip through the front of both slipped stitches simultaneously, from left to right.
- Knit them together through the back loop with the right needle.
The slipping-knitwise step is important: it twists each stitch individually before they are worked together, which creates the correct left-leaning orientation. If you slip purlwise by mistake, the ssk will not lean cleanly to the left.
Why SSK is Often Looser Than K2tog
This is a widely known asymmetry in knitting: ssk tends to be slightly looser and less tidy than its k2tog counterpart. This happens because the mechanical action of the ssk — inserting the needle from left to right through the backs of two already-slipped stitches — is slightly less compact than the direct insertion of k2tog.
Several fixes exist:
- Skp (slip 1, knit 1, pass slipped stitch over): An older left-leaning decrease that some knitters find produces a tighter result than ssk. The lean is slightly different — try both on a swatch and use whichever looks cleaner in your specific yarn and gauge.
- After-the-fact tightening: If ssk consistently looks loose in your finished work, use a tapestry needle to tighten the ssk stitch by pulling excess yarn from the neighboring stitches.
- Blocking: Wool ssk stitches even out significantly with wet blocking.
- Inserting the needle differently: Some knitters get a tighter ssk by inserting the needle through both slipped stitches from right to left instead of left to right, effectively doing a modified version that produces similar lean with less looseness. Experiment on a swatch.
K3tog: Right-Leaning Double Decrease
K3tog (knit three together) removes two stitches at once, just like k2tog removes one. Insert the needle through three stitches simultaneously and knit them as one. The result leans to the right. It is fast to execute and produces a sharp, angular decrease suitable for pointed lace motifs, V-neck shaping where a quick decrease is needed, or any situation where you want to remove two stitches in one spot with a rightward lean.
The tension of k3tog can be tight — working through three stitches at once provides more yarn resistance than two. If your needle struggles, try inserting one stitch at a time onto the right needle and then knitting all three together; this is sometimes called a "setup" method and provides better needle access.
CDD: Central Double Decrease
CDD (central double decrease) removes two stitches while remaining visually balanced — it neither leans left nor right but creates a vertical centered stitch with decrease lines radiating symmetrically outward. This is the decrease used in the center of symmetric points: the center of a shawl's tip, the center stitch of a neckline V, the crown of a cap with a perfectly centered star.
The method:
- Slip two stitches together knitwise (insert the needle through both as if to k2tog, then slip them without knitting).
- Knit the next stitch.
- Pass both slipped stitches over the knitted stitch together.
The center stitch (the knitted stitch) rises to the top, flanked by the two decreased stitches on either side. In lace motifs and at the points of triangular shawls, the visual clarity of cdd is noticeably superior to any other double decrease method.
When Symmetry Matters
In raglan shaping, neckline shaping, and any garment or accessory where decreases appear on both sides of a center point or a structural line, the lean of your decrease should follow the direction of that line.
The convention: decreases on the left side of a shaping line lean left (ssk or skp). Decreases on the right side lean right (k2tog). This creates a clean visual line where the decreases appear to follow each other, rather than opposing each other and creating a jagged edge.
This is what patterns mean by paired decreases: k2tog on one side, ssk on the other, placed so that the lean of each decrease mirrors the lean of its partner. On a raglan sweater, looking down at the work, you should see four clean diagonal shaping lines — two leaning right (k2tog), two leaning left (ssk). When the wrong decrease is used, the shaping line zigzags instead of flowing.
What "Paired Decreases" Means in Patterns
When a pattern says "work paired decreases" at a neckline, it means: use ssk on the left front and k2tog on the right front (or vice versa, depending on whether the shaping is done on a knit or purl row). The stitches slope toward each other, converging at the center of the neckline like an inverted V.
When a pattern says "work decreases symmetrically" around a yoke or at the crown of a hat, it means: whatever decrease you use on one side, mirror it on the opposite side. If the pattern is ambiguous about which decrease to use, choose k2tog for right-leaning positions and ssk for left-leaning positions.
Quick Cheat Sheet
- K2tog: Right-leaning single decrease. Tight, tidy, works anywhere.
- SSK: Left-leaning single decrease. Pairs with k2tog for symmetric shaping. May need blocking to tighten.
- K3tog: Right-leaning double decrease. Two stitches removed at once. Sharp point.
- CDD: Centered double decrease. Balanced, vertical center stitch. Use at the tip of anything symmetric: shawl points, V-necks, hat crowns.
Once you understand what each decrease does visually, the instructions in any pattern stop being arbitrary abbreviations and start being logical choices that you can anticipate and verify as you go.