Double Decreases are a hallmark of lace knitting and are also used in highly textured stitch patterns. There is usually more than one way to work the same double decrease but some “interchangeable” decreases do look a little different. Below are several for you to choose from. Experiment with the different decreases to see which one looks best for your application. As with EVERYTHING in knitting, the easiest one to work isn’t always the best choice. In the decreases below, all directions refer to the slant when viewed from the right side or public side of your work. The below swatch shows each decrease...read on to see which is which and how to work them.
Left Leaning Double Decreases – Made on a Right Side Row
sssk - slip 3 sts knitwise, one at a time, return sts to left needle, knit all 3 sts together through the back loops. (Decrease 1)
s1k2p – slip 1 st knitwise, knit the next 2 sts together, pass the slipped st over decreased st (Decrease 5)
Left Leaning Double Decreases - Made on a Wrong Side Row
sssp - slip 3 sts one at a time knitwise, return all 3 sts to left needle. With right needle behind your work, insert needle from left to right through the back loops of all 3 sts and purl 3 together through the back loops. (This is equivalent to the sssk that is worked on the right side.) (Decrease 3)
p2tog psso - p2tog, slip next st knitwise to the right needle, then return it to the left needle in its new orientation. Return the decreased st to the left needle then pass the st to the left over it and off the needle. Slip decreased st back to right needle. (Decrease 7)
Right Leaning Double Decreases - Made on a Right Side Row
k3tog – knit 3 sts together (Decrease 2)
skpp - slip 1 st knitwise, k1, pass the slipped st over the knit st, return this decreased st to the left needle, pass the second st over the first and off the needle. Slip decreased st back to right needle. (Decrease 6)
Right Leaning Double Decreases - Made on a Wrong Side Row
p3tog - purl 3 sts together (Decrease 4)
sp2p - slip 1 st purlwise, purl the next 2 sts together, pass the slipped st over the decreased st. (Decrease 8)
Central Double Decrease – Made on a Right Side Row
s2kp - slip 2 sts together knitwise to right needle, knit the next st, pass both slipped sts over st just worked and off needle. (Decrease 9)
Central Double Decrease – Made on a Wrong Side Row
s2, p1, p2sso – slip 1 st knitwise, slip next st knitwise, insert left needle from right to left and return sts to left needle, p3tog. (Decrease 10)
You’ll notice that the Central Double Decreases tuck the decreased stitches neatly behind the center column and there is little difference in appearance when worked from the right or wrong side row. You might enjoy this article on complex lace too!