I’m weaving two 78″ (on the loom) scarves with Cascade 220 fingering-weight wool in a 2/2 twill weave, one scarf right after the other. I’m noticing the floating selvedge threads, one on each side, are getting progressively tighter. I’m almost finished and think I’ll make it but would like to avoid this in the next set. I wonder if the selvedges going over and under successive weft picks while the rest of the warp threads in the body are doing their 2/2 pattern with the weft is the cause.
In the next pair of scarves should I have the floating selvedge threads slightly longer and separate from the warp on the back roller and use weights to maintain the proper tension?
That is a REAL mystery, and I’ve never known it to happen. I’ve used many floating selvedges with twills, even twills with longer floats than 2 threads, but the floating selvedges have always gotten looser, not tighter. It must have something to do with the yarns and setts and the way that floating selvedge is actually “weaving.” Usually, the floating selvedge remains straight in the cloth even though the weft is going over/under it. Most of the time the weft is really just going around it.
But I see two solutions to your situation. One is, as you suggest, to take the floating selvedge away from the warp beam and let it hang, weighted, from the back beam.
The other solution would be to eliminate the floating selvedge altogether. If you have threaded 1-2-3-4 from right to left, say, so that first thread on the right is a 1 and the last thread on the left is a 4, you don’t need a floating selvedge. So that the edge threads always interlace:
Raise 1-2 and weave from left to right.
Raise 2-3 and weave from right to left.
Raise 3-4 and weave from left to right.
Raise 1-4 and weave from right to left.
If you have threaded in the reverse direction (another example of the Plague of the Opposites as mentioned in Friday’s Ask Madelyn), reverse the shuttle directions. You might have some other threading/treadling system than a straight draw, in which case, some can be worked out similarly, others maybe not.
If you’d like to learn more about floating selvedges and how to determine when to use them when weaving twills, I highly recommend Robyn Spady’s video Totally Twill: The Basics.