20 years of folding signatures and I just learned grain direction matters that much
I started binding in my garage around 2002, mostly rebinding old paperbacks and making journals for friends. Nobody ever told me about grain direction. I just cut whatever paper I had, folded it, trimmed it, glued it up and called it done. Some books felt fine. Some were stiff and the covers would warp after a few months, which I blamed on humidity or cheap board.
Last spring I took a weekend workshop in Portland with a woman who's been doing conservation work for decades. She watched me fold a single signature and asked, 'Do you know why that's curling?' I said no. She flipped my paper so the grain ran parallel to the spine, refolded the same sheet, and it lay flat like a totally different material. I felt like an idiot standing there in her shop with all these warped books I'd made over the years.
Since then I check every sheet before I cut. Not all paper has obvious grain, but now I run the bend test on everything. My last three journals came out flat and the covers haven't budged. Anyone else get far into this craft before figuring out grain? What did you do with all your crooked books, just live with them or redo the covers?