How to make the etching in the middle of the acrylic?

[jkopel]

It is done with a different kind of laser.
The light emitted by a CO2 laser (like a Glowforge) is absorbed at the surface of the glass, but other kinds of lasers are able to focus in the middle and create tiny pits.

We actually had a discussion about this a while back, but it was under a different topic:

Can it engrave quartz crystal?

Interesting, I stand correct on the shattering bit. at least as far as regular glass is concerned… I found a few youtube videos of other companies that offer lasers to do this, and they don’t appear to be using CO2 lasers (the green beam color is probably a giveaway). [Creating 3D images inside glass blocks] That one says they use a vanadate laser, but there is a wikipedia article that says YAG lasers will work as well. (I am excited to get a glowforge and I do a lot of g…