Today I did some engraving on stainless steel using Cermark LMM6000 black. I first cleaned the surface (which was orbital sanded) with acetone. I then applied a single, light coat of Cermark.
then etched some samples. I found the process to be fairly tolerant of speed and power settings, but I settled on the Speed=1000, Power=full (OR 100 worked well too). Resolution of 340 lip
I have no idea if it’s Cermark but I’ve had a Yeti tumbler for about a decade and the obviously laser-marking has held up just fine. It shows a little physical wear from various cupholders over the years.
People coat firearms components with a similar product (cerakote) which is baked-on, and it’s pretty much considered “lifetime”.