You might ask: Why?
Answer: Because now I can :)
And besides that I can mark all sides. Even the one used for closing the clip.
I previously used stickers for that. Guess what: they didn't stick. Now, the marking is permanent.
Settings used for engraving: Balsa (preset engraving parameters).
Also got feedback from the nice people at Mr. Beam: If the laser misses parts of the lettering (which happened to me when choosing a smaller font size) increase pierce time.
Which I hadn't set because I hadn't thought about the material's color: White.
Oh, and the stuff in the photo is made of PVC. So don't take these.