trapping long floats in stranded colorwork

One of the questions I get most often from students or knitters working from my patterns is how to trap floats in stranded colorwork. I thought it would be a good idea to finally address this issue!

Firstly: what is a float, and why would I need to “trap” it?

“Float” is a common term for the strand of yarn that runs across the back of colorwork fabric - the strand that makes colorwork stranded. This distinguishes it from other colorwork methods like mosaic knitting or intarsia. Typical stranded colorwork motifs are worked with two different colors per round, with the colors changes happening often (this keeps the floats short). Some motifs, however, involve longer floats - and long floats are exceptionally good at catching on fingers, jewelry, or other things that can work their way between the knitted fabric and the float. So for knitted fabric that’s likely to come into things that may catch on floats, like fingers and toes, we must trap or catch long floats to anchor them to the fabric.

Here’s a visual for you:

In the swatch pictured above, there are two long floats where the blue yarn is stranding across twelve stitches on the wrong side of the fabric. The long float pictured at the top of the swatch is trapped twice so that the blue float never carries across more than four stitches (it looks like three shorter floats instead). The long float pictured at the bottom of the swatch isn't trapped at all, so it's floating across all twelve stitches. You can see how much easier it is to catch a finger (or a toe, or a hand) on the open, un-trapped float:

So, if I’m knitting a piece that has long floats, how often should I trap them? I get this question a lot, and it’s a tricky one to answer. Some teachers use hard-and-fast rules, like “never carry a float more than five stitches without trapping it.” Some teachers tell you not to go more than three stitches. Personally, I don’t like this approach. It may sound precise at first, but when you think about it, gauge makes this an incredibly imprecise way to go about it. A float carried across five stitches in fingering weight is a much shorter float than one carried across five stitches in bulky yarn. If you must use a general rule, going by length in inches or cm is a better way to go (e.g. making sure no floats are longer than 1” or something similar).

That being said, if a rule doesn’t jive with your personal preferences, that’s perfectly fine! I don’t enjoy trapping floats very much, as it slows down my knitting and can affect the look of my knitted fabric, and I’ll avoid it if I can get away with it. The most important thing is to consider what kind of item you’re knitting, and who’s going to be wearing/using it. A pattern like Pine Bough Cowl is worked in a tube and then grafted together, so the floats on the inside of the tube will never be exposed one it’s finished - there’s really nothing they can get caught on. No need to trap floats there. A baby sweater or a pair of mittens, however, will provide ample opportunity for fingers to catch on floats, so trapping those floats is a good idea. There’s a big difference between a knitted bag you’ll sew a lining into and a pair of mittens or socks. Use your best judgment and go with what you’re comfortable with!

Now that we’ve covered when it’s a good idea to trap floats - how do we actually do it? In reality, there are a few different methods, but I’ll be demonstrating what I think is the most common below. Because I’m a continental knitter and I carry both yarns in my left hand, that series of photos is first, but if you scroll down you’ll also find a series of photos demonstrating the same technique in the two-handed method, with one yarn carried in each hand.

I’ll be using my Hearth Slippers to demonstrate in the photos, as this pattern involves a very long float the first time you work Chart C. I’m working the Large size, and the float is carried across 21 stitches. The charcoal grey is the working yarn for that length, while the light blue yarn is being carried across the back (the “floating” yarn). In this example, the dominant yarn is the floating yarn, while the background yarn is the working yarn. (Wondering what the “dominant yarn” is? You can read about color dominance here.)

CARRYING BOTH YARNS IN THE LEFT HAND

I’m trapping my float every 6th stitch as I work across the span of charcoal grey, but you could trap every 5th or 4th stitch as well. You can see in the photo above that I’ve worked the first 5 stitches of my 21-stitch span.

Insert your right-hand needle into the next stitch, but don’t wrap your working yarn around the needle yet.

Slide your right-hand needle underneath the floating strand (blue), then wrap the working yarn (charcoal) around your needle to knit the stitch.

If you stop here and look at your float, you’ll see that it’s caught in the space between the stitch you just knit and the previous stitch. You’ve effectively trapped the float already!

Go ahead and knit the next stitch normally. When carrying both yarns in the left hand, you may need to use your thumb to hold the floating yarn (blue) out of the way. After knitting this stitch, I have 7 stitches of my 21-stitch span knit. My blue floating yarn is trapped on either side of the 6th stitch. This is a very secure way to trap the float.

Here’s a closer look at what that looks like from the wrong side of the fabric:

You can see how the float is trapped at the sixth charcoal grey stitch.

And you can see these steps in action here:

trapping long floats - carrying both yarns in your left hand from Dianna on Vimeo.

CARRYING YARNS WITH THE TWO-HANDED METHOD

In this example, the dominant color, carried in my left hand, is the contrasting color (blue), while the background color, carried in my right hand, is the main color (charcoal). The background color/main color is also my working yarn here, while the dominant/contrasting color is being carried across the wrong side of the work.

Insert your right-hand needle into the next stitch, but don’t wrap your working yarn around the needle yet.

Slide your right-hand needle underneath the floating strand (blue), then wrap the working yarn (charcoal) around your needle to knit the stitch.

If you stop here and look at your float, you’ll see that it’s caught in the space between the stitch you just knit and the previous stitch. You’ve effectively trapped the float already!

Go ahead and knit the next stitch normally. After knitting this stitch, I have 7 stitches of my 21-stitch span knit. My blue floating yarn is trapped on either side of the 6th stitch. This is a very secure way to trap the float.

Here’s a closer look at what that looks like from the wrong side of the fabric:

You can see how the float is trapped at the sixth charcoal grey stitch.

And you can see these steps in action here:

trapping long floats while using the two-handed stranded colorwork method from Dianna on Vimeo.

There are other ways to trap floats, but in my experience, this is the most common (and it's a pretty simple way to trap floats as you're working, so there's less finishing after the fact). If you finish knitting something and only then realize that you should have trapped the long floats - don't worry! It's possible to trap those long floats as you're weaving in ends after the fact (and if there isn't a long end to weave in where you need to trap a float, you can take a spare bit of leftover yarn and just weave it into the wrong side of the fabric as if it were an end, trapping the floats as you go).

Feel free to post questions in the comments, or share other tips or methods you know of!