The two knitting stitches SSK and SKPO are interesting ways to make a decrease lie in the opposite direction to K2 together. SKPO is in fact the older technique which still appears in many lace patterns and will often be found in older classic style patterns with lines of double decreases. SKPO is a short form of "slip 1, knit 1, pass slip stitch over" which is also often abbreviated as sl. 1, K 1, PSSO. SSK was introduced by Barbara Walker in her wonderful Second Treasury of Knitting Patterns in the 1970s and basically stands for slip, slip, knit. Many variations of these two stitches have been invented to create all sorts of ways of decreasing the number of stitches in your work and it is useful to know how to work them.

Let's first look at their appearance. In the picture above, the top ten rows show a line of SSK decreases. These lie very smoothly, and can be almost indistinguishable from Knit 2 together. The bottom section (just above the garter stitch) shows a line of SKPO decreases which you can see is much more defined than the SSK and would not match a line of Knit 2 together stitches as closely. This will be invaluable knowledge when we come to look at double decreases!

SKPO

To work SKPO first of all place the right hand needle into the next stitch as if to purl.

Slip this stitch onto the right hand needle, but do not knit it.

Now, knit the next stitch as normal.

Insert the tip of the left hand needle into the slipped stitch.

Lift this stitch over the first stitch on the right hand needle.

SSK

To work SSK first of all insert the right hand needle into the first stitch on the left hand needle as if to knit.

Lift this stitch onto the right hand needle without knitting it. Repeat this action with the next stitch on the left hand needle. You will have two twisted slipped stitches on the right hand needle.

Insert the left hand needle through both the slipped stitches from the back.

Finally knit the stitches off together as if they are one normal knit stitch.