I am now weaving some 8-shaft twill samples on the remainder of the blanket warp. I am not using a temple. The selvedges appear to be perfect. Both selvedges. Not just the right. The left as well.
This is the same warp on which I wove the blanket. I did a double-stick header which allowed me to remove the blanket while keeping the threading and sleying intact.That heading also allowed me to tie the sticks back on the apron rod without tying (and re-tensioning) the whole warp again. I learned how to make this heading from Peggy Osterkamp's Warping Your Loom and Tying on New Warps, Number 2. The result is the same even tension across the width of the warp that I had when I wove the blanket. Also I am using the same end-feed shuttles.
There are two differences. The first is that I am using different tie-ups. I don’t see how this could affect the selvedges, especially since I am still using separately weighted selvedge warps on each side.
However, here is the second difference: I removed some of the edge warp threads. So, instead of weaving on a 43” wide warp, I am weaving on a 33” wide warp.
Could the different width really have such a marked effect on selvedges? I remember reading somewhere that one shouldn’t weave the full width of the loom. I don’t recall why. And since my computer is still in the hospital, I can't check to see whether or not I made a note of that information. The weaving width on my loom is 45”. 43” is precariously close to full width. Perhaps there is a relationship between arm span and throwing a shuttle properly? Perhaps I didn’t have the tension set quite right on the shuttles? I will have to keep this issue in mind as I weave future projects.