@MightyBear It's not really engraving the metal but it does add pigment to the surface. There are commercial products like Cermark / Thermark that do this but they are expensive, using acrylic paint or markers is a cheap alternative but a bit hit-and-miss on results. I make a solution from brasso cleaning fluid and alcohol that seems to work well with my CO2 but not so good with the diode laser.
@DavidF Hi David, sorry for delay been working my socks off decorating the house. and I hate decorating lol.
I'm in the UK down south in New Forest, if your interested then give me a shout on email. email@example.com Regards Tug