The YAG laser you are talking about removes material. I am adding it.

The process I use is called CerMark. I have placed photographs on Polished Stainless Steel with it for Christmas presents. If I decide that the picture is not up to my standards I can tell you the stuff is VERY hard to get off. It takes sandpaper and a LOT of elbow grease. Even a buffing wheel doesn't take it all off no matter how much you try.

It is resistant to scratching, salt water, lubricants, and if you can believe the ads, a blow torch. The spray is fused by the laser into a ceramic material.

Google CerMark.

The initials you see on the blade above look much better in person. The photo is showing them almost 4 times the real size.