I have an engraver, but it is cumbersome on metal labels, and more difficult to read. For the several hundreds of blinds labels I use each year, a simple pencil is quick, easy to use, and always available. Press hard if you use #2s. Paint pens seem to be good and at least as long lasting (only tested 3 years so far), but the point isn't fine enough for all my data. Pencil is great on vinyl blinds, but is not very permanent on aluminum blinds. The surface isn't porous enough, and the graphite rubs off and smears easily.
