I have done metal stamping a few times. I’ve learned a little bit about what makes it easier to do.
I was having trouble with the copper stamping and I could not find any help about it, so I’m hoping this will help someone and is findable by people needing help.
Firstly, metal choice. It’s easier to stamp on some materials, like aluminum. Blanks are often aluminum. Here is a helpful chart for hardness (doesn’t include gold probably because most blanks would be just gold plated). Two things about colored aluminum are: 1) it’s only colored on the surface, so when you stamp it’ll be silver, and 2) if you try to do my coloring the letters technique, it’ll scrub off the color. Another tip: try to practice once or twice if you can, to get a feel for how it goes.
Second: getting everything in line. There is stamping “tape” available for this purpose. I think (or at least what I’d do is) I’d set the stamp down and nudge it until I can feel it touching the tape. I obviously didn’t do this for any of my projects. I am not sure how to get the kerning right though (the horizontal space between letters). I suppose if you were really meticulous, you could write everything beforehand with a Sharpie and after each letter, put tape vertically to align with the letter’s left edge. You can remove the Sharpie with running alcohol.
Actual stamping: Try to do it with just one strike. Even if you think it didn’t move, it did and you’ll have a double letter.
Here’s my #1 tip. ***Use a jewelry anvil or another piece of hard metal under the metal being stamped.*** I tried the copper stamping on a rubber block several times and could not figure out why it wasn’t working. I guess there’s just too much give. I couldn’t get the number to impress hardly at all. With the force of the hammer, I imagine the stamp just pushed the metal into the rubber instead of impressing the number. With the anvil, there is nowhere else for the force to go but the stamp. This is the problem I couldn’t find any help about and I’m glad I finally figured it out. I had the physics backwards in my mind and thought the stamp would go in better with a softer base.
For coloring metal impressions, I have always used a Sharpie. I didn’t color the copper one, but I did the other two pictured. To get the extra that gets in the non-stamped surface, I just sand it with fine steel wool (you won’t have a glossy finish if you do this). You could use rubbing alcohol, but you’d have to be careful not to get it in the indentations. I think alcohol ink works well for coloring metal, too, and you could probably wipe the surface gently to remove excess, but I haven’t used alcohol inks before.
Overall, just expect your first few to look pretty rustic. In my opinion, this is a craft that requires a lot of experience to become pretty good at it.