In my last post I talked about using fishing line under special circumstances. When I said that it prevented draw-in, I was incorrect. What the fishing line does is more effectively to keep the warp ends at the selvedge so spread out during the actual weaving that the draw-in is equalized across the entire warp enough to result in selvedges that look (hopefully!) the same as the rest of the fabric.
Now, why wouldn't one always want to do this? Isn't this a desirable effect? Well, it certainly was in my case, where I wanted to made virtually invisible joins between panels of fabric. But otherwise I don't think it is usually desirable. The closer draw-in at the selvedges serves a very important purpose: to protect the edges of the fabric. The edges of a fabric are the most vulnerable to wear. The cuffs on men's long-sleeved shirts are a good illustration. So having the warp on the edges of a fabric a bit closer than the rest is really a good thing. I have read of weavers who actually sett those edges closer for just that reason.
A warning about my posts. I am always learning. What I say here today may well be different next year. I may have learned, for example, that my current skills (or lack of them) at winding on warps may have been leading me to use a temple as a crutch. I don't think so, but it's always possible.
An example of always learning. I "know," and have "known" for a long time that one is supposed to move the warp frequently while weaving. Every 1 1/2" to 2 1/2" are the general guidelines I have read. Sometimes I kind of abide by that; sometimes I don't. The temptation to weave and weave before I finally am forced to move the warp forward is very great.
Today as I watched the weaving of the blanket progress, I noticed something I had not noticed before. As I wove, the angle of the weft thread kept getting smaller and smaller. The left selvedge also started getting pretty bad. Now I "know" that the angle of the weft thread affects the amount of weft pushed into the fabric. And I "know" that the less weft pushed in, the more draw-in there will be. But this morning, knowing started turning into understanding.
So I moved the warp and after about 1" of weaving, I noticed the selvedge beginning to tighten up. So each time after I threw the shuttle, I used my free hand to pull up the weft thread closer to the reed. This made the angle of the weft about what it had been in the previous inch. It worked!
Now that I finally understand a bit more, moving the warp frequently will not bother me, at least wide warps. My suspicion is that a narrow warp can be woven a bit longer before having to move it. But I will have to test that out.