There are many knitters who will look at that subject heading and feel really uncertain about it. If you’ve just painstakingly knit some fabric, being careful to not drop stitches, it can feel wrong! But there are in fact times when it comes in handy, especially when working with knitting that’s most easily done in the round, but you want to end up with flat fabric.
I’m not going to go intoall the details here; there’s lots of instructions out there for how to cut a steek (and what a steek is), My goal is to talk about the basic principle of why it works and why your knitting won’t suddenly turn into a pile of unraveled wavy yarn if you follow good instructions. (I recommend trying it out with small samples and swatches first.)
So the first question is: why doesn’t finished knitting fall apart? The answer is that it’s held together at all the edges by something: the various cast-ons and bind-offs use special techniques to keep stitches from running, grafting also holds things together, and the selvedges don’t come apart because the yarn is either continuous, or any ends are worked in so that they don’t come loose.
Here is a piece of flat knitting with selvedges, a cast-on, and a bind-off. It’s one long piece of yarn, and all the edges are secured. The yarn is toothy; if I washed it on hot with agitation, the fabric would be fulled (the technical term for turning finished fabric into something that looks like felt). I have in fact washed this sample once; this helps stabilize the fabric.
But what happens to a piece of flat knitting in toothy yarn without selvedges, cast-on, or bind-off?
I’ve cut the selvedges off the swatch. So far, so good. Knit fabric doesn’t run sideways, only vertically. If I handle the edges really roughly, it will start to make a fringe, but I’m not going to do that. If the edges fray enough, the fabric will come apart, but this kind of fraying only happens when there’s nothing keeping the strands of yarn from spreading apart at the edges.
Here I’ve cut the bottom and top off. The worst that’s happened so far is that the top edge has started to curl. If there’s nothing securing a stitch at top or bottom, stitches can run vertically, leaving ladders. Stretching the fabric horizontally will especially make this happen. If there’s no bind-off, then all the stitches can run, eventually. If there’s no cast-on, it depends on what kind of knitting stitch pattern is used. (Try unraveling k1/p1 ribbing from the bottom sometime and see how far you get.)
I picked up the swatch by each corner in turn and shook it vigorously. I even stretched it a teeny bit horizontally (not vigorously; that would make the stitches run). It’s curling a teeny bit more, and that’s fine. The edges are starting to get a bit messy. I’m actually surprised by how well this held up!
The good news here is that I’ve never heard of people suggesting making reckless horizontal cuts in knitting. Usually there’s some care, involving putting stitches back on needles as soon as possible. This is usually only necessary if removing or adding some extra length from a sleeve or something.
I’ve bound off both top and bottom, and I’ve worked a chain stitch up each side of the sample in thinner yarn. The chain stitch acts like an artificial selvedge. The sides have started to fringe because I’ve handled the edges while stitching them, but overall they’re more secure.
There’s a gap in the bind-off at top and bottom because I’m going to cut the swatch one more time. I’ve added vertical reinforcement stitches to either side of where I’m going to cut; there’s more ways to do this than chain stitch. Reinforcing it ahead of time gives even more assurance that the cut won’t fray.
And here’s the last cut.
If this were a real project, I would either do something to cover the reinforcement stitches and cut edges, mostly to make it look better, or I would pick up stitches and knit at a right angle to the original knitting, hiding the reinforcement stitches and cut edges a different way.