PSA: linen thread vs. waxed cotton on a 300-page rebind, and the linen held up way better
I rebound a beat-up 1970s dictionary last week using 18/3 linen thread and it laid flat with no gaps at the spine. My first try with waxed cotton thread kept slipping and I had to re-sew two sections. The linen cost about $12 a spool but it was worth it for a book that thick. What thread do you all use for heavier text blocks, or do you switch to something else for big jobs?