Sett: How does sett affect image?

How does sett affect image?

When someone says they’re weaving at 8 epi, that is the sett. That means they have 8 warp strands in one inch. I define sett a bit more in my last blog post on this topic

Weaving is a gridded structure. The images we make have to fit onto the grid formed by the warp and weft.

Ever wondered why a horizontal line in tapestry is wavy? This turquoise line illustrates it.

Because the structure so easily forms squares, making other shapes is more challenging in tapestry weaving. But of course we do want to weave something besides squares!

Consider the two diagrams below. Let’s pretend that each square along the top indicates one warp thread. When building a shape like a circle, we have to make little steps. With only 8 warp ends in an inch, those steps are fairly large visually. Of course it should be noted that though the number of warp threads are easily visualized by the columns, weft passes do not equate to the vertical distance shown here. Each tapestry sequence creates a little rectangle and many of them must be stacked up to cover the vertical distance indicated by these squares. If I wove one sequence for every row in these circle diagrams, the resulting form in tapestry weaving would be a very squished oval.

The fewer warp ends per inch in tapestry, the more stepped the resulting vertical lines and curves will be.

Now what if we doubled the number of warp ends in an inch? Those steps are much smaller aren’t they?

With more warp ends per inch, the steps are smaller and the perceived curves or diagonals are smoother.

The more warps you have in an inch, the smaller those little steps can be.

This fact is the most important thing to understand when you're choosing a sett for your tapestry design. Horizontal lines are easy to make in tapestry weaving. Vertical lines are not! Any curve or shape that is more than about 30 degrees can't be outlined eccentrically and will be composed of little steps. Even if you're not using outlining in your work, shallow angles and curves can be made to look quite smooth if you pay attention to hill and valley threads. But once you get above about 30 degrees, steps are going to form.


There are a few technical tricks to minimize those steps, but the steps will never entirely disappear. Perhaps we should embrace this stepped nature of tapestry instead of constantly trying to get rid of those stairs!

A few tapestry examples

The piece below is by Marcia Ellis. I saw it last year at the San Jose Museum of Quilts and Textiles in a show concurrent with American Tapestry Biennial 11. This piece was woven sideways (the shiny elements are beads).

Marica Ellis, SuperNatural, tapestry

Imagine the piece is on a loom in this direction. The warps would be running from bottom to top, the way I'm showing it below (with apologies to Marcia for turning her work for illustration purposes!).

Those big sweeping curves in yellow and green, work very smoothly in the weaving. The blue arrow points to these curves.

The vertically woven curves are much more stepped. The red arrow indicates one of these curves.

Marcia Ellis, example of horizontal and vertical curves in tapestry weaving

Below is a detail of this piece that shows this a little better. I have turned the piece sideways again. Please do go back to the first image of this piece to appreciate the way it is supposed to be viewed after looking at the detail.

In the detail it is easy to appreciate the stepped nature of the brown and red forms as they move over and see how much smoother the shallower angle of the yellow is.

I found Marcia's gallery notes about this piece completely appropriate to this discussion.

Tapestry is built on a grid: the warp is vertical and the weft crosses it horizontally. Unlike computer screens, the “pixels” are not square because the weft packs down and creates a small rectangle as it crosses the warp. Curves are difficult to execute in this medium. SuperNatural is an image that requires curves to flow as if they were not constrained by the grid.
— Marcia Ellis

Any angle or curve you're weaving that is steeper than about 30 degrees at setts of about 8 to 10 epi will start to make little steps. As you change the sett, this becomes more or less extreme.

If you are weaving at a wider sett like 6 or 4 epi, the number of steps in an inch is decreased even more and you'll see steps at even shallower angles.

But if you wanted to weave a lot of vertical things and make them as smooth as possible, you could use a finer sett. The more warps you have in an inch, the smaller those steps get.

Many people love to do small format work and often they choose a finer sett to accommodate more detail. No one currently does this with quite the skill as Kathe Todd-Hooker. The piece below is fairly large for her--over a foot square. But the detail is quite astounding. I don't know the exact sett of this piece, but my guess is that it is well over 20 ends per inch. The gold maze lines are done with soumak.

Kathe Todd-Hooker, Safe Haven, 13.5 x 12.5 inches, dual duty craft thread, embroidery threads, metallic threads.

Below is a detail from this piece, Safe Haven, which I saw in American Tapestry Biennial 11 in San Jose.

Tapestry size and viewing distance

There is one last thing I'd like you to consider here. The size of the tapestry will naturally dictate the distance from which a viewer will want to study it. For very small works, people tend to get up close to see them better. For large works, standing back is natural to take in the entire piece. When further away, the human eye will blend the lines and create a smoother effect in the brain than what actually exists in the weaving. If a smooth gesture is represented even if it is made up of little steps, we will understand the line as a smooth curve from a distance. Small-format weavers have no such advantage. I believe this is what leads many small-format weavers to weave at such fine setts. People are examining their work from very close and so to make their lines smooth, they have to decrease the distance between each warp end. This results in setts like 18, 20, or even 32 epi. If you have a warp sett of 32 epi, you're probably using a fine silk or sewing thread as weft.

Of course it is completely possible to weave a very large tapestry at a fine sett. This last example was also in ATB11. I believe it was woven at about 14 epi and is 59 x 75 inches. Gabriela Cristu, Prelude to the Afternoon of a Faun. (I've always wondered if she loves Debussy also.)

Gabriela Cristu, Prelude to the Afternoon of a Faun, 59 x 75 inches, wool and cotton.

Below is a detail. It was woven sideways. If you look carefully, you can still see the steps, but this piece is so large, it looks like it was painted when you stand at a normal viewing distance.

Gabriela Cristu, Prelude to the Afternoon of a Faun, detail

This is not to say that a fine sett is necessary for small format works. Many weavers produce marvelous small pieces at 8-10 epi. For one example, consider Sarah Swett's recent weaving of tiny houses. They are 2.5 inches square and I think she is approaching 30 of them now. You can see more of them on her blog.

Sarah Swett, tapestry weaving, 2.5 x 2.5 inches, four-selvedge warping technique.

What will your choice be?

Sett and design go hand in hand. If you really want to weave very detailed images in tapestry, then you may be a natural fine-thread weaver. If you love the grander scale of large-format as I do, then your sett can get wider if you want it to. I have a lot of opinions about what sorts of things work well as woven tapestry, but I also believe that every artist has to figure that out for themselves. So get practicing!

Play with what forms you can make at a particular sett. Go and see tapestries in person if at all possible. Get close and try to figure out what the sett was and then think about how the forms were created. The ATA unjuried small format show is the next great opportunity in the USA to see a lot of tapestry at once. The show will be up during Convergence in Reno, NV in July and there will be a catalog. And if you can't travel, start with THIS.

What setts do you like to weave at and why? Tell us in the comments.

These are all the posts on this topic. If there is a link, the post is already up.

Warp and Weft: A cooperative relationship in tapestry weaving
Sett: What does it have to do with tapestry weaving?
Sett: How does sett affect image?
Sett: Materials and yarn choice
Sett: Looms and tools
Sett: Recap. Why does it matter again?