How to choose the best reed (and sleying order) when the perfect reed is not available

Many weavers have a limited number of reeds available to them.

If you have a 12 dent reed, and the project you are working on has a 24 epi Sett, you simply sley 2 ends in each dent. Easy peasy!

What happens if you DON’T have the perfect reed available?

Example 1:

Anne Hiemstra ran into just this situation while participating in the Angles and Unduls Weave-along for Academy members. She posted a the following question to the group:

“I’m using 8/2 tencel at 28 EPI. I have 10, 12, and 15 dent reeds. Is one of them preferable over the others?”

My usual M.O. is to figure out how I’d need to sley each of the reeds available to get the desired result and choose the one with the fewest numbers in the sleying repeat. The denting calculator, available to Handweaving Academy members, works a treat for this!

Use the denting calculator

If I put Anne’s numbers into the denting calculator, this is what I get:

  • 10 DPI: 2-3-3-3-3
  • 12 DPI: 2-2-3
  • 15 DPI: 1-1-2-2-2-2-2-2-2-2-2-2-2-2-2

Consideration 1: Length of the sleying repeat

My first instinct would be to choose the 12 dent reed because it’s got the shortest sleying repeat: just three dents per repeat, rather than 5 for the 10 dent reed, or a jillion for the 15.

A short repeat is good for two reasons:

1. It’s easier to remember and to check while you’re sleying.

2. It means that the “odd man out” (the dent that’s different from the others) happens more frequently, which means the density of the warp is more consistent all the way across.

When the odd man out happens infrequently, that means the majority of your warp is sleyed one way, with only occasional exceptions.

Yes, the warp threads will move around and adjust to some extent, but they won’t move that much or that far. If the exceptions are few and far between, my gut tells me that the warp won’t even out to the desired sett as readily as it will when the exceptions are closer together.

Most of the time, the length of the sleying order is all I worry about. If I’m still not sure, or I have a couple of equally good options, I might take things a step farther.

Example 2:

Now say that the desired sett was 24 ends per inch rather than 28, and that the 12 dent reed isn’t available. In that case, the denting calculator (such a handy tool!) tells me that my sleying options are:

  • 10 DPI: 2-2-2-3-3
  • 15 DPI: 1-1-2-2-2

Consideration 1: Length of the sleying repeat

Both of these have five dents per repeat, so that isn’t helpful for choosing in this case.

Consideration 2: Number of ends per sleying repeat

In the 10 dent reed, the sleying repeat is 2+2+2+3+3 = 12 ends. In the 15 dent reed, it’s 1+1+2+2+2 = 8 ends.

Suppose I’m planning to weave rosepath and this is my threading:

This threading has eight ends per repeat. If I choose the 15 dent reed, the sleying repeat also has eight threads per repeat. Having a threading and sleying repeat of the same length will make it easier to spot both threading and sleying mistakes as I’m dressing the loom.

Now suppose instead that I’m going to weave summer and winter, and this is my threading:

In this case, my threading changes every 12 threads. The 10 DPI reed has a sleying repeat of 12 threads. Using the 10 dent reed instead of the 15 will make it easier to spot threading and sleying mistakes while dressing the loom.

Rearrange exceptions to make things more uniform

Notice that the denting calculator lists the number of ends per dent from lowest to highest, which means that all of the exceptions are at the start or end of the list:

  • 2-3-3-3-3
  • 2-2-3
  • 1-1-2-2-2-2-2-2-2-2-2-2-2-2-2
  • 2-2-2-3-3
  • 1-1-2-2-2

When there’s only one exception per repeat

When there’s only one exception, there’s usually no benefit to rearranging things, because multiple repeats will even things out automagically.

For example, if my sleying order is 2-2-3, four repeats look like this: 2-2-3-2-2-3-2-2-3-2-2-3. The 3 appears every third dent.

If I rearrange the sleying order as 2-3-2, then four repeats look like this: 2-3-2-2-3-2-2-3-2-2-3-2. The 3 still appears every third dent. It’s the same pattern as before, it just starts in a different spot.

Usually it makes no difference where you start in the pattern, so there’s no benefit to rearranging things to begin 2-3 instead of 2-2. If rearranging the sleying order would make it line up with your warp yarns or colors, though, it might still be worth thinking about.

When there are multiple exceptions per repeat

When there are multiple exceptions in each repeat of a sleying order, it’s usually a good idea to rearrange the numbers to space the exceptions out as evenly as possible.

If my sleying order is 2-2-2-33, three repeats look like this: 2-2-2-33-2-2-2-33-2-2-2-33. The 3s are grouped together and further apart. If the threads are grippy and not inclined to shift around, you might wind up with thinner columns where the warp is sleyed 2-2-2 and thicker columns where it’s sleyed 33.

If I rearrange it to 2-3-2-3-2, however, three repeats look like this: 2-3-2-3-2-2-3-2-3-2-2-3-2-3-2. Now the 3s aren’t grouped and are spread out more evenly. Most of the time, 2 and 3 alternate, with the occasional spot where there are two 2s together.

This pattern of 2s and 3s in the second version is more uniform, which means the fabric will be more uniform even if the threads are grippy and don’t want to shift around much.

To sum up

When you don’t have the ideal reed for a given sett, follow these steps:

  1. Make a list of the reeds you have available.
  2. Figure out the sleying order for each of your options.

If one of the options is much shorter or simpler than the others, great: there’s your answer.

If you’re still not sure, then:

  1. Eliminate any long or confusing sleying orders.
  2. Compare the number of ends per repeat of the sleying order to the number of ends in your threading repeat. If one is a match, a multiple, or a divisor of the other, that’ll help you avoid threading or sleying mistakes.

Regardless, if your sleying order has multiple exceptions (more than one dent that’s different from all the others), then rearrange it to space the exceptions out as evenly as possible, keeping in mind that the pattern will repeat over and over.


Academy Members can learn more from these lessons:

Sett and Yarn Size

Typical Setts for Common Weaving Yarns

Twill Ratios and Sett