In the category of "I've been working on that. Slowly." we have Bombyx silk, dyed in peacock colors (the green and purple don't really show in the picture, but they're there). This is a three-ply yarn and this is the third skein. One of these days I need to measure the skeins and see how much yardage I have and how that compares to what the peacock feathers shawl wants. Memory says about 1500 yards of laceweight, but we all know how flakey my memory has been lately.
Sylvia, I think you're right about the mixed single needing more twist. It's an artifact of the mixing of fibers - the merino/silk paired against merino/silk is fine but the merino/silk paired against the pure silk isn't. The pure silk wants more twist than the merino/silk does and I'm putting the same amount into both. I'm not sure what the effect of adding more twist to one part of the single vs another part of the single would be - any insights?