Coins on Craig Andera

Laser Engraved Coins

Thu, 13 Aug 2026 00:00:00 +0000

I've been engraving metal coins with my little fiber laser. It's so good for engraving.

First experiments (December 2024)

It took a few tries, but in December 2024 my experiments started to yield better results. This coin has a gear border around an open notebook and pen.

And the same coin from the top.

Later (August 2026)

Some more recent examples: a couple of coins with engraved portraits. I darken the recesses with brass black and then run them in a rock tumbler for a bit to remove the black in the raised portions.

Hacker B&B Coin

Tue, 29 Apr 2025 00:00:00 +0000

This is one of my favorite projects ever. It's a custom brass challenge coin, and only one was ever made. It was a gift to my hosts at something called the Hacker B&B, a gathering of friends that is one of the highlights of my year.

The AI-generated image on the back signifies games, scotch, presentations, and food, four of the popular pastimes at the event.

Both images are converted from flat 2D art to a depth map using SculptOK, an AI-based depth map generator. I tried quite a few other approaches, and nothing came close.

Polished

After lasering, the coin goes into a rock polisher for an hour or so. It does a good job of cleaning out the soot from engraving.

But the final look is much improved by an application of "brass black", followed by about twenty more minutes in the polisher. Gives it a bit of definition and age.

Brass Yes/No Coin

Sat, 21 Dec 2024 00:00:00 +0000

I've always liked custom coins. I've made a few, and this was one of the first. I sometimes referred to it as my "binary decision generator", and I used to carry it around with me.

And the other side.