Yep greyfox, this was my exact concern also. I have personally spoken to all of the people that own these hydrographic places and was told that they also use automotive grade sealers overtop of the camo paterns, anyhing from a very dull satin to a very shiny clearcoat.
I have looked at a few synthetic rifle stocks that were dipped and cleared to look like exhibition grade walnut ect. And was amzed by it! The camo patterns are awesome also. Im sure most companies can use the same processes, i beilieve you would be very happy with the outcome.
Here are a couple of the websites that have sample pictures of some of he items they have dipped, should give you an idea of what patterns ect.
Liquidillusions.com out of chambersburg PA.
Extremeliquiddesigns.com out of Needmore PA.
I know they are dar from you but should have similar products as the ones near you.