I’ve also tried Cermark, but you can’t get any shades of gray there, only monochrome.
I really do not know anymore
it seems to me that the metal is getting too hot (material changes color)
But as I said, sometimes it works without problems and sometimes not even though I don’t change the settings
Day to day (and even hour to hour) variances in annealing results are discussed and fairly well known. A couple of degrees or a change in a few percent relative humidity can throw off the results for this type of marking (or laser annealing) with everything else being precisely equal.
There are compounds other than Cermark that some users have success with.
Molybdenum Disulfide lubricants and organics with sulphur such as mustard (strange but true) have been recommended.
I would not hesitate to attempt preheating a stainless steel blank on the hot dashboard of a car or in a toaster oven to see if I could improve repeatability.
