I was checked with Oldblades back in July about laser etching he told me that you needed a yag or fiber laser to mark on blade steel .The local engraveing shop uses a CO2 laser to mark USMC K-Bars it just cuts thru the black coating on the K-Bar blade He also said that it could be engraved with a dimond drag but the engraveing would be shallow. Oldblades told me that he has a Co2 laser and that the etching would rub off after a while. I am still looking for someone who has a yag or fiber laser to do the work I want done.