Central Double Decrease (CDD)
Central double decrease (CDD) reduces three stitches to one in a single step, typically used at the center top of hats and in lace patterns.
Explanation
Central double decrease (CDD) reduces three stitches to one in a single step, resulting in a stitch that sits straight and symmetrically on top, unlike decreasing twice in a row. You slip two stitches together as if to knit them together, knit the next stitch, then pass the two slipped stitches over. The technique is often used at the very center top of a hat to create a neat, symmetrical crown, and is also common in lace and leaf motifs.
Also known as: CDD, sl2-k1-p2sso
How to work a centered double decrease
Slip two stitches together as if to knit them together, knit the next stitch, and pass the two slipped stitches over. Three stitches become one, and the middle stitch ends up on top.
It is precisely that middle stitch on top which gives the technique its character: a straight, clear line with no lean to either side.
Where it is used
CDD is used in hat crowns, at the center of shawls worked out from the neck, and in patterns where two lines should meet at a clean point. It removes two stitches at a time, so the count drops quickly.
In lace it is often paired with two yarn overs, one on each side, so the stitch count stays constant.
Common mistakes
- Slipping the stitches individually, which destroys the centered effect.
- Forgetting that the decrease removes two stitches rather than one.
Keywords
- central double decrease
- CDD
- double decrease
Frequently asked questions
How does CDD differ from two ordinary decreases?
CDD gives one straight, centered line. Two ordinary decreases give two lines leaning opposite ways.
Where is a central double decrease used most?
Hat crowns, the center of triangular shawls, and patterns where a vertical line should run through the shaping.