Vent: picked linen thread over synthetic for a 400 page rebind and I regret it
I was rebinding a beat up 400 page novel for a friend and stood in my shop for 20 minutes deciding between waxed linen and that bonded nylon thread everyone pushes now. I went with the linen because I liked how it felt in my hand, and honestly the sewing went fine. The problem showed up 3 weeks later, the spine has a slight sag in the middle signature and I can see the thread gaps when the book sits open. My buddy who runs a bindery in Denver told me the nylon has just enough stretch to keep tension when the paper swells. Anyone got a thread they swear by for thicker text blocks, or do I just need to sew tighter?
Man, I have to disagree on the thread being the problem here. Linen has been the standard for hand sewing books for like a hundred years, and plenty of thick text blocks hold just fine with it. Nylon stretch sounds nice until it relaxes over time and your tension goes soft, that stretch cuts both ways. The sag you're seeing sounds more like a loose signature or too few sewing stations on a 400 page block, so I'd check your stitch count and how tight you pulled before you blame the thread.