decrease

In knitting, a decrease is the deliberate removal of one or more active stitches from the working row, accomplished by passing one stitch over another or knitting multiple stitches together. The primary purpose is to reduce stitch count and thereby narrow the fabric, a technique essential for shaping garments at armholes, necklines, sleeve caps, and foot decreases in socks.

The two main methods differ in their mechanics and directness. A knit two together (K2tog) merges two stitches into one by inserting the needle through both loops and forming a single stitch; this leans the resulting stitch to the right. Conversely, a slip, slip, knit (SSK) involves slipping two stitches knitwise individually, then inserting the left needle through both from left to right and knitting them together; this creates a leftward lean. Machine knitting employs mechanized decrease cams that automatically suspend and discard stitches across the needlebed.

Rate and pattern matter in fabric appearance

Decreases distributed evenly across multiple rows create vertical lines and smooth contours, while clustered decreases produce sharp points or pronounced shaping. The frequency of decreases determines how quickly the fabric narrows; rapid decreases over few rows generate steep angles typical of hat crowns, while gradual decreases over many rows produce gentle curves suitable for raglan armholes. Uneven decrease placement causes fabric asymmetry and visible irregularities that undermine garment fit.

The directional bias of different decrease methods affects visual balance in shaped pieces. Mirrored decreases, in which rightward-leaning decreases pair with leftward-leaning ones on opposite sides of a centerline, produce symmetrical vertical detail and professional finishing. Without intentional directional control, the eye perceives visual imbalance even when stitch counts are correct. Machine knitting typically produces symmetric decreases through synchronized needle action rather than intentional hand maneuvers.

Common problems arise from improper tension or dropping stitches during the decrease process, which leaves unraveled loops or creates ladders in subsequent rows. Decreases worked too loosely result in loose stitches that distort shaping and appear sloppy. When multiple stitches are involved, such as in central double decreases or industrial gathered decreases, the sequence and order of stitch suspension directly determines final appearance and structural integrity of the narrowed section.