You may not have noticed it, but I bet you've seen it: when you look at the ribbed cuff of a striped sock, somewhere, buried in the hollows of the purl ditches – blips! That's right: blips!
By blips, I mean those annoying little spots of the wrong colour distorting and breaking up the lovely and otherwise clean lines of your stripes.
Blips don't happen where the yarn changes colour in stocking stitch, just where the sock is ribbed. Actually, that's not quite true. They DO happen in a stocking stitch part of the sock, they just happen on the inside. Check it out for yourself: next time you pick up a pair of striped socks, turn them inside out, and check out what is happening to the purl bumps where one stripe meets another. See it? An entire row of blips! But that's okay: they are on the inside, and therefore, out of sight. Park that thought: we'll circle back to it shortly.
So why do they happen at all? Well, it's all to do with how the loops of one row of knitting interact with the loops from the row above it, or below it. On the inside of that sock, you can see that when the upward-pointing loops of one colour interlock with the downward-pointing loops of the other colour, they cross over each other. The result of this is that you see some blips of the lower colour above the upper colour, and some blips of the upper colour beneath the lower colour.
Turn the sock back the right way out, and that's what is happening in the purl ditches of your rib. You can think about the purl stitches on the outside of the sock working in the same way as the purl bumps do on the inside.
And this is where the fun starts...
We can use these facts to our advantage. If it's true (and it is) that the blips only occur where there are purl bumps showing, then in order to eliminate them from the outside of our sock, we need to eliminate purl bumps from the outside of the sock too.
But hang on: I want ribbing, and that needs purl bumps. Right! But look again at the inside of the sock. The blips only happen where two stripes meet. That means that we only need to eliminate purl bumps at the point when the row we are working is a different colour from that the row below it. After that, it's business as normal!
So here's the solution: At the point in your sock where your yarn changes colour (if using self-striping yarn), or when you decide to add a stripe of a new colour (if you are striping the sock yourself), don't rib, just knit one complete round. It doesn't even need to happen at the start of the round – if your yarn changes colour mid-round, simply stop ribbing at that point, and work one complete round of knit stitches until you get back to the same point, and you can start ribbing again. The golden rule is simply this: If the stitch you are working into is the same colour as the yarn you are using, rib as normal. If, however, the stitch you are working into is NOT the same colour as your working yarn, don't rib, knit instead! Easy, right?
But doesn't that affect the integrity of the ribbing?
Actually, no. Think of garter stitch. It looks like all purl bumps, but actually contains rows of knits sandwiched between rows of purls. The knit rows get swallowed up between the purl rows either side, and you can only see them if you pull the rows away from each other. The same thing is happening here. That rogue knit round will totally collapse between the two rows that contain the purl stitches above and below it, and consequently, it will disappear entirely.
Essentially, by doing this, we have sent all those pesky blips to the inside of the sock, where no one will ever see them, and if you look inside a sock that employs this technique, you will see all those banished blips, hanging out and looking rather dejected and forlorn. They know you've won the battle!
About our expert
Nathan Taylor, also known as Sockmatician, is a designer, knitting teacher and podcaster who enjoys exploring sock construction and double knitting techniques.