is engraving on mirrors with a diode laser, is that bad for the laser ??
Never put a real mirror under your laser diode. This can be dangerous to you and can damage the lens and other internals of your laser diode. Same goes for a CO2 laser too.
Mirrored acrylic with its masking on is fine.
If you mean a real glass mirror, you would need a bottom reflective mirror. Effectively there is a layer or coating on the back of a mirror that provides the reflection, you’d etch off this coating from the back and your engraving will then show when looking at the front. People who do this sometimes spray paint the back side so that a solid colour shows through.
Yes indeed, people sometimes do that.
These are for the community cat room (Kitty City) at our local shelter.
The blue one goes inside The City and the red one in the entryway.
Done with 80w CO2.
Very nice @Hank I like that result.