Reka-
If I can remember correctly we did some of these for a client some years back. I can't remember the opacity but here is a good rule of thumb.
White backing equals very vivid images with great color saturation...as you already know with cutting boards.
Semi-Opaque will result in a more translucent finish....unless you mount it on top of white.
Contact the vendor and ask what the backing /coating looks like; the above info should give you a representation of what results you can expect.
If they can not describe what the coating looks like....you may want to look for another vendor
Hope this helps,
Jae