Serious question, how long did it take you to fix a spine that kept cracking on the first open?
Back in 2019 I bound a run of 12 journals with a tight back and every single one cracked right down the hinge the first time it was opened. I thought it was the grain direction so I re-cut all the boards, then I blamed the paste and switched to a different wheat starch, then I spent two weekends testing spine linings. It turned out the real problem was the mull, I was using a thin muslim that had no stretch and it was fighting the boards every time the book moved. Total time from first crack to the fix was about 7 weeks, which feels silly now because the answer was a heavier crash cloth and a hollow back. I still have two of those wrecked journals on the shelf as a reminder. Has anyone else lost weeks to a spine problem that ended up being one dumb material choice?