Dropped $140 on a cast iron book press from a guy in Fresno, and it's the only reason my last batch of journals lays flat
Spent six months folding signatures with a cheap wooden press and every spine came out lumpy, so I finally drove out to Fresno and handed over $140 for a used cast iron one off Craigslist. Now I'm wondering if anyone else made the jump from wood to iron, and what weight you're running for thicker signatures.
Switched from a cheap wood one to iron about two years ago and honestly I still think wood gets a bad rap, it just has to be a good hardwood press with thick plates, not the flimsy basswood ones most people start with. My old maple press actually did fine on 4 to 6 sheet signatures, it was only when I went to 8+ sheets that things got lumpy because the plates would bow in the middle. Iron does clamp more even, mine's around 40 pounds, but a lot of what you paid for is just the flatness and staying flat over time, wood can warp if your garage gets humid. So yeah, iron is nice, but idk if it's the only reason your journals lay flat, the six months of practice folding probably helped too.