Knitted slip stitch structure

I’ve been writing a series of posts about knitting stitch structure:

And now I want to move on to a mildly more complicated question.

Four strands of yarn with the start of a column of knit stitches in the center. The bottom two strands have been made into stitches. The blue strand would usually be next.

Having made these two loops, what happens to the middle strand if the next loop I pull through it is made with the top strand instead of the next one up?

There’s actually several interesting possibilities, and I’m not going to include all of them in this series of posts. (Not least because the ones I’m leaving out are harder to draw!)

I’m going to talk in this post about slipped stitches, and then next time I’ll start talking about brioche stitch.

So, to pull the top strand through the last loop made, I have to move the bottom loop upward. (When knitting on the needles, this loop is slipped from one needle to the other without knitting it, hence the name slip stitch.) So what happens to the un-knit strand of yarn?

illustration of one column of stitches in four rows of knitting. The third strand of yarn from the bottom has not been knit, and the strand of yarn is in front of the stitch it would have been pulled through.
click illustration to enlarge

All kinds of things can happen in the neighboring stitch columns that I’m not showing, but in the context of slipped stitches, that middle strand can either form a horizontal bar in front of the slipped stitch, making for a decorative bit of texture (and sometimes color, depending on the yarn), or

illustration of one column of stitches in four rows of knitting. The third strand of yarn from the bottom has not been knit, and the strand of yarn is behind the stitch it would have been pulled through.
click illustration to enlarge

It can form a horizontal bar behind it. This is basically invisible if the yarn is essentially all the same color, or if the yarn is extremely variegated in color, because it adds a little extra variegation to the stitches.

In both cases, the amount of yarn in the bar that sits in front of the stitch or behind it is shorter than the amount of yarn that would ordinarily be used to form a new stitch. Also, the stitch that is slipped is made bigger because it has to stretch to reach the next row. I didn’t show that in the illustrations above, however.

In these illustrations I’ve shown the slipped stitch in a bigger context. What I haven’t shown is that the extra yarn to make that slipped stitch stretch has to come from somewhere. It usually is pulled from the stitches on either side, which makes them a bit smaller. (If this isn’t desirable, the stitch that’s going to be slipped can be originally knit as an elongated stitch —wrap the yarn around the needle an extra time.)

There you have it, for now anyway. If you’ve done brioche knitting before, you might know the path that blue line is going to take when I draw the illustrations, or you might not. I hope to make things clear!