"A man without hope…is a man without fear.”
Daredevil: Born Again
Acid etching with vinegar and fingernail polish.
Start with a container of white vinegar big enough to submerge the parts you want etched (or the whole knife).
paint desired pattern on with nail polish (color doesn’t matter it’ll all etch black).
Submerge steel in vinegar and let it sit a day or two.
it’s as easy as that.