Why does nobody talk about grain direction showing up after the glue dries?
I was at the bindery in Portland last Tuesday and a guy named Ray, who has been doing this for 30 years, picked up my finished copy and ran his thumb across the cover. He asked me which way I folded the endpapers, and I said I didn't think it mattered once the paste dried. He just shook his head and showed me how the paper had cocked a bit along the spine because I ran the grain the wrong way against the board. I went home and checked six books I made last month, and four of them had that same slight warp I had been blaming on the humidity. Now I am second guessing every sheet I cut for the past half year. Does anyone else catch this only after the press is closed, or do you test the fold before you glue anything down?
Man, I used to wave off grain direction too, figured paste and pressure would just flatten it all out once it dried. Then I noticed the same thing you did, covers curving a bit toward the board on stuff I'd already shipped, and now I check the fold before anything gets glued. Ray sounds like he saved you a lot of headaches down the road.