I'm wondering what happens with the laser when you are trying to engrave or cut reflective surfaces, like metals or glass? Does the laser reflect back to itself and possibly cause some damage, or do we need to cover the reflective surface with something, so that the laser doesn't get reflected?
Hugh
@dan explains it best below, but things that are reflective to visible light aren’t necessarily reflective to the Glowforge, and visa-versa. So glass and normal mirrors should be fine. Hard Drive Disks, not so much.
@hughmcl , you might also want to look at some of the other threads here on what you can and can’t do to glass and metal. It has been a pretty big topic of discussion!
The best bet is to use the search, but here are a few that you might want to read.
Hard Drive Disks, not so much. 