They sure have some wild patterns!
I have a two hydro-filmed stocks done by Bell and Carlson. One is a Ti stock the other a lightweight Ruger McMillan. The material that B and C uses is pretty darn tough. Many gun cleaning solvents have dripped on the finish with no ill effects. I have the natural gear and freedom tan.
Bell and Carlson
One interesting thing I discovered is that you can write on the surface with a sharpie of various colors to change the effect. By using a patch with some brake clean solvent the color can be blended in. Once dry it is quite durable. If you get tired of those colors you can easily remove by rubbing harder with a patch of brake clean.
B and C's Snow natural gear would be a great one to use for color changes.
IIRC the price was $60 to cover a stock.