What's required to etch it, is dependent on if the entire billet is stainless, and the type(s) of stainless in the billet. I find it a little suspicious that complete instructions for heat treating AND etching were not included with the purchase.... usually reputable Damascus makers/sellers include those directions with any order/purchase.
If the entire billet is an austenitic stainless (hardenable), I suspect you are going to have to get into some pretty harsh/dangerous stuff to get a good etch. Not that I'm encouraging it, but things such as muriatic acid, heated to just below it's boiling point..... and that is the "mild" stuff. From there on out, you just increase your health risks/hazards.
I looked up the products, and it appears he/they are using non ferric alloys in the mix?? I guess to each his own, but from the standpoint of usability, putting non-ferric alloys into a pattern welded situation is not the wisest choice one could make.
