Relief etching can do some wonderful things to the edges of a plate, but how do you print it with those rough/sharp edges? I made a kind of jig from the fall-out of a matboard opening. These already have a 45˚ angle on the edges, which mimic the beveled edges of an etching plate, and the 4ply board equals approximately the thickness of a 16 gauge metal plate.
First, trace the outline of the plate and then cut that shape out. After inking the plate, drop it into the hole in the board. Align the paper with the registration marks on the board and print!