I used to print a little signage at our tiny sign shop. And I built all of our electric signs from scratch. Angle iron, sheet metal, surplus oil field pipe, plastic, electricals, and paint. We didn't have an oven, so panned plastic faces we subbed out, then decorated in house.
So I know a little sheet metal, but much less flat stock printing and I cringe at some of the procedures I used to employ. I always always always used God's (93 million mile away) exposure unit. Possible but finicky.
I also printed quite a few jobs on wooden frames, coated with homemade sheet metal scoop coaters. Years ago.... Trap? Spread? Choke? I might have guessed that was Mayonnaise that went down wrong. But I'd never heard of those words.
Anyhow, Welcome!