Once you’ve got experience with a particular yarn, it’s pretty easy to decide what sett to use for a new project. Want it firmer than whatever you’ve done before? Increase the sett. Want more drape? Open the sett up. Changing the tie-up to one with more or longer floats? Increase. Change to a structure with more interlacement? Decrease. Etc.
If you’ve got lots of experience, you might also be comfortable extrapolating from one yarn to another. The logic might go something like this: “I used 8/2 cotton/hemp at 16 EPI for those Bronson lace towels and really liked the hand. Now I want to use this 8/2 tencel. The cotton/hemp was hairier than regular 8/2 cotton, and this Tencel is slinkier than 8/2 cotton, so for a similar kind of fabric, I should probably nudge the sett closer by a couple of steps, from 16 to 18 to 20” Another version is “I don’t know what this is, but it’s definitely an animal hair fibre and feels a little heavier than the wool I liked at 12 EPI so I guess I’ll try 10.”
But what if you don’t have any relevant experience to go on – how do you figure out a sett then?
Copy from someone else’s playbook
I tell every weaving student in my classes about Handwoven Magazine’s Master Yarn Chart, which is my go-to resource for making decisions about sett. Handwoven has compiled a list of “all the yarns that have been used in Handwoven magazine projects since 2000. Numbers indicate yards per pound, meters per kilogram, and a range of setts—from wide as for lace weaves, medium as for plain weave, and close as for twills,” and then generously made this resource available for free online. (It hasn’t been updated since 2014, but there’s still a wealth of information therein.)
For instance, here are listings for 8/2 cotton, both mercerized (pearl) and unmercerized:
Those three numbers at end of each listing are the setts: 16 for lace, 20 for plain weave, and 24 for twill. Each of the three ought to produce a well made cloth when woven as a balanced fabric (i.e. the same picks per inch as ends per inch) in the corresponding structures.
Note that these setts are not the right setts, they’re suggested setts. They’re a starting place from which you can begin to make adjustments based on the purpose of your fabric, your combination of yarns in warp and weft, etc. They’re a good first stop on your sampling journey, but they may not be where you wind up.
You may also be able to get this information from published projects in books, magazines, kits, or even on Pinterest. The take away here is that in many cases you don’t have to reinvent the wheel; unless your yarn is really unusual, chances are someone’s already done the legwork for you.
Doing your own legwork
If you don’t know what your yarn is, or you want to verify a sett you found somewhere online, or you simply like legwork and making your own decisions, you can figure this stuff out for yourself, too.
The most common advice is to wrap your yarn around one inch of a ruler, count the wraps and then use half that number for plain weave or 2/3rds of it for twill. The numbers make sense but my problem with this has always been how tightly you pack the yarn on the ruler. It’s yarn. It’s got squish. How much should you squish it? I’ve tried this ruler trick several times and am only really confident I’ve gotten the “right answer” when I already know what answer I’m aiming for, which is not very useful.
There are other ways, and here again someone may have already done some of the work for you. A lot of yarn comes wound onto spools or cones with each successive wrap lying right alongside the one before it. If that’s the kind of yarn you’ve got, you can measure it right on the spool.
Lay a flexible measuring tape perpendicular to the wraps on the spool and pin it in place so you don’t have to hold onto it while counting. Then count the wraps in an inch, or in half an inch if there’s not a full inch exposed and easy to count:
pin the measuring tape onto the spool…
…and count the wraps.
This is 8/8 unmercerized cotton, which is 840 yards per pound (YPP); the Master Yarn Chart suggested setts are 6, 8, and 10.
You can pretty easily count the wraps in the photo on the right: there are 17 in the inch. Which means that this yarn ought to work at half that number – 8 or 9 EPI – for plain weave, and at two thirds – 11 or 12 EPI – for twill. I’ve woven with 8/8 at 10 EPI for plain weave; it’d work for twill too, but I suspect the 11 or 12 would work just as well – depending, as always, on what you’re using for weft and what degree of drape you’re aiming for. If you want a firmer fabric, go with the higher number. If you want a fabric with more drape, choose the lower.
If your yarn is very fine, it can be nearly impossible to count the wraps on a cone. It may help to take a picture with your cell phone and crop it right to the ruler, thereby making the threads big enough to see and easier to count:
This is 20/2 silk (Master Yarn Chart suggested setts: 22, 26, 30). At this scale, I count 23 wraps in that half inch, which is definitely in the same ballpark as the MYC numbers. I wove lace with this yarn at 20 and was very happy with it; I’d probably choose 22 EPI for a plain weave with drape. I suspect that this yarn woven as plain weave at 26 EPI would be quite sturdy.
If your yarn isn’t wound smoothly onto a spool or cone like this, you pretty much have to do the winding yourself – but you don’t have to do it onto a ruler with its sharp, square edges. A smooth, round dowel will be much easier to work with.
You also don’t have to try to guess how much to pack the yarn together; instead, you can intentionally space it out so that there’s a gap between each wrap that’s the same width as the yarn itself and then not divide that number in half because you’ve already effectively done that.
One last tip: I find that, if I don’t let the yarn stack on top of itself on the pegs of my warping board but instead make them lie side by side, they tend to move together or spread out and reach a kind of spacing equilibrium – and often that spacing is about what I want them to look like on the loom, under some tension. I use this to double check my intended sett before I get to the loom, and may even adjust my plans based on what the threads try to do on the pegs.
This is particularly useful when I’m winding a mixed warp and am trying to judge what good sett for the combination of yarns might be.
In this case, I wound a warp for twill fabric out of four different yarns at a time. As you can see by counting the shiny, silky gold threads, there are six sets of four, or 24 ends total, in one inch. That’s the sett I wound up using and it worked well.
Speaking of mixed warps, if you’re mixing yarns evenly across the web, as in the example above, then an excellent sett to start sampling at is the average of the setts appropriate for each of the constituent yarns. The warp above was a mixture of 5/2 cotton (MYC: 18), cotton chenille (MYC: 18), 8/2 rayon flake (MYC: 24), and a slinky possibly viscose that I thought was finer but is actually a little heavier than that royal blue 20/2 silk (MYC: 30) further up the page a ways. A little heavier + a little slinkier means that the same sett ought to be good. The average of 18, 18, 24, and 30 is 22.5 EPI, which would also have been a great sett for this combination of yarns.