Saturday, February 27, 2010

Selvedges on Jacquard Weaves

When I weave twills on the 24-shaft loom, whether they're the compound twills that I get with the interleaved threadings or just fancy twills, I always use a 2x2 basket weave selvedge:

This gives a nice, clean edge to the cloth and guarantees that every weft shot interlaces the outermost warp thread of the clot on both sides of the cloth. The "extra" end in the inner edge of both selvedges prevents over-long floats at the intersection of body and selvedge. If the body of the cloth is 2/2 twill, the extra end isn't needed, as it's possible to match the twill and basket so they meet and greet politely.

In talking with several jacquard weavers, I've asked what they do for selvedges. Most say they don't do anything special - just design the pattern area right out to the edge. Which means that on structures with longish floats, like 8-end or longer satin, most weft shots turn around several ends in from the edge. I tried a couple of pieces like this, not worrying about a selvedge treatment, but found that it made the edges of the cloth curl toward the back, sort of like stocking stitch all the way to the edge behaves on knitted cloth.

So I've been experimenting with various structures for jacquard selvedges. A faux floating selvedge can be incorporated by sacrificing a one-pixel-wide column on each side of the design and filling it with plain weave. This works, but it doesn't take up at the same rate as the body of the cloth, so the outer end needs to be weighted separately.

If the structure in the body of the cloth is shaded satin with a single weft, then my old standby 2x2 basket works fine. Sometimes I'll make it a 3 (wide) x 2 (high) basket and sley it a little looser than the body of the cloth to help it take up the same as the satin. However, in the case of a structure with more than 1 weft system (such as the weft-backed satins I've been using lately) I have to stretch the basket vertically, so it ends up as a 2 (wide) x 4 (high) basket to account for the 2 wefts. I don't want to sacrifice a whole lot in width, so I've reduced the basket to 3 threads: 2 for the outer part of the basket and 1 for the inner part. Again, that extra thread prevents (or at least reduces) the floats at the intersection of body and selvedge.

I used this 3-thread basket selvedge on the maple leaves, and am much happier with my edges.

You can just see the characteristic sideways V shape (like a < symbol) at the edge, with both weft colors showing where they make the turn. I suspect that when I begin weaving with more than 2 wefts, all I need to do is stretch the structure accordingly, and it'll keep doing its job of tidying the edges.

1 comment:

Alice said...

Satins are also useful for selvedges. Even though they don't catch every thread every time, the regularity of the interlacement gives a nice edge. This works especially well with multiple wefts. Depending on the frequency of interlacement of the main weaves, you might try 5-end satins, 8-end, 10-end, etc. until you find the one with the same rate of interlacement of your main weaves.