Before you even begin, you need to figure out how big you want your pleats to be and to account for this in your design through increases or extra cast on stitches. Because each pleat comprises of several folds, the number of stitches you will need for each pleat is 3 times the width. The pleats I’m demonstrating here are 3 stitches wide, which means that each pleat will be made up of 9 stitches.
Once you have accounted for that, you just follow these steps to create the pleat. There are a number of other ways this could be accomplished, but this is the one I find to be the most straight forward and tidy.
First, knit to where your first pleat will begin.
Then slip the first 3 stitches of the pleat onto a cable needle or DPN.
Do the same thing to the next 3 stitches, on a separate cable needle or DPN.
What you do next is simply fold your knitting so that the two double pointed needles are stacked underneath the left hand needle. To do this you’ll need to twist the middle needle.
The direction you twist it and the order in which you stack your needles will determine the direction your pleat folds. The directions in the pleated yoke pattern specify folding them as an S or Z, this is a demonstration of what that means.
After the stitches are tidily folded, you do something very akin to 3 needle bind offs, only more of a 4 needle bind off. You simply knit (or purl, as the case may be) the three stacked stitches together.
You repeat that step over the next two groups of stitches, effectively turning 9 stitches into 3 and creating a tidy little fold.
Depending on how you space your folds, which direction you place them in relation to each other, etcetera, you can create some pretty neat effects. Even just placing the pleats in the same direction or facing each other has a big effect on how they look.
Once you bind off, the pleats are nice and structured. It would be fun to play with not binding off, too, and using pleats as fabric manipulation in the middle of a piece. Ah, the possibilities…
It takes a bit of planning, but the results are worth it.