An etched copper presentation certificate

Five years ago, a dear friend designed the logo for my business, which I subsequently protected with a service mark. Although I paid her for her work I wanted to say thank you with more than just money.

Having an interest in decorative etching (among other steampunk pretensions), I decided to etch the service mark from the patent office into a 9 x 12 sheet of solid copper. After trying to transfer etch resist to the plate a number of ways (transparency and newsprint and a hot iron didn’t give sufficient quality), I finally hit on success after BrantH suggested I spray paint it, and remove the paint with the laser cutter. Here’s the process from start to end.

First, the plate was spray painted with gray primer. I originally tried Krylon, but I think it was ironically too durable, and resulted in a poor etch on the first attempt. I had to buff that out and start again. It also led to an interesting conversation at the hardware store, where I had to explain why I wanted a “less durable paint.”

Once the plate was painted, I laid out a border in Corel Draw, and imported the image downloaded from the USPTO. Then the design was cut from the paint. After some trial and error on smaller test pieces, I used speed 40%, and power 40% on the 50 watt laser cutter.

After the completion of the cut:

Once the cut was complete, the plate was bathed in a solution of 1x muriatic acid, 2x hydrogen peroxide. I eventually ended up making about three times the amount of solution shown here in order to get a stronger reaction.

This is after the etch was completed. You have to watch and determine when you have a sufficiently deep etch, it took me about 30 minutes.

The final proof the etch is deep enough is unfortunately only when the paint (acting as etch resist) is removed using acetone. If it’s not deep enough, get out the buffing wheel, and start over. This time however, it works!