RE: can you scorch paper/canvas if you shoot it at close range?
You could stretched a piece of canvas tight in a frame and then shot it with a patched roundball, you'd get the hole. The amount of fire and powder stain would depend on the distance you shot. Too close and the pressure will tear the canvas but I doubt burn it. Maybe smoke it good. Too far and the flame and powder would disperse before it made your art.. It might be fun to try. As for paper, I think anything close it would just tear it up.