Ideally I like a material like this:
those available for sale nowadays are pretty bad, except for Spiftire of course, but it is too expensive for me right now.
So I started experimenting with DIY methods.
The first experiment was using clear epoxy resin and liquid pigments, and initially this is what I got (using only 2 colors, so not really deep color variation):
not bad for the first try (not really tortoise shell, but still I prefer this to printed tortoise pickguards)
but by the time the resing was cured, the colors were all mixed togheter and it resulted in a plain/single color layer. So the method is not quite right.
Do you have any suggestion?
I think next I will try using acrylic colors on a thin layer of plastic, and cover it with clean resin only once the colors are dry.
Or maybe try again with resin but using colors only once the resin is almost cured.
... Good Luck 
- I wouldn't be able to go that way... 
- I tested Acetate material to make vintage 40s Archtop pickguards in "Flakes" and "Flamestripes" patterns with a good success...
