Wow that is a really nice piece.

There is a chapter in David Boye's "Step by Step Knifemaking" about acid etching. There are also many amazing pictures in the book of pieces he and a few of his co-knifemakers have worked on. It's an older book, but very well written and worth a look . I picked it up to read before I start my attempt at crafting a Sgian Dubh. I feel it's going to take me many practice attempts before I came remotely close to the lovely one in this thread!

Thanks for sharing,
Sara