I used to use an etched mark and it worked just fine.
Then started making slipjoints, and pretty small ones at that...my stencils no longer fit the tang area on a small slipjoint, so found a fellow who delt in used
"New Hermes" pantograph style engravers and purchased one. It was probably in some jewelers store for 40 or 50 years before I bought it.... It is size adjustable and uses a diamond tipped stylus, so I can engrave my mark (last name), the blade steel type, and "KMG" which means I am/was a voting member of the Guild when I made the knife, as one of the last steps in making a folder...already heat treated as I grind all my blades after heat treat.
Ernie Grospitch was mentioned as a maker of stencils. From what I have seen of Ernie's work and heard about him as a maker/person, even though we haven't met face-to-face yet, I could easily recommend him.