here's a little piece of a message I found posted by pinlicious in rgp:
. you are basically clearcoating over a sticker. that sticker get one air bubble on a spot where it
didn't adhere to the wood, and you are going to have major issues. go ahead, roll the dice...
Now, the guy that printed my RoadBlasters artwork suggested this to me:
he said to clean the sides of the machine real well, then get a spray bottle with a little soap and mostly water in it, and wet the side of the machine slightly. Then apply the sticker to that. Use a squeege to get the air bubbles out then let it dry for a few days. and you're good to go. If you apply the same idea to a pinball PF it sounldn't be too hard to ensure those air bubbles are out of there. Then I guess you use some automotive poly.
I dunno. Getting into what's the best way to apply a sticker and what to poly it with seems like maybe a topic better suited for the main forum. Not burried in here with artwork.

I don't really wanna ask though, because so many people have the attitude of "I don't like that" so when you ask what's the best way to do it, their answer is "don't".
Allroy