I didn't have a bubble problem with mine, but sold the game after a while so don't know how it stands up to abuse. It still looked great after a year or so.
But anyways, what I did was print with a regular ink jet printer onto some peel & stick paper (HP
Invent It Peel & Stick project paper to be specific, though it's not really anything special). Then I applied a layer of clear peel & stick stuff to that, then cut out to size and it was ready to peel off the backing and apply. Good thing about this is for my application I needed white, so the paper provided that.
Here's a picture of the machine I did this on:
http://callkck.com/pb.htmProbably no help at all for insert graphics, but for what it's worth... It worked on my drop targets and the rest of the opaque art very well.