Marble Magnet Air Bubbles

[dahliablue.livejournal.com]

I recently started making marble magnets and I made one batch that went well. However, it seems I've run into a problem that I just can't seem to solve. I think air is getting trapped in between the picture and marble, making air bubbles that look very translucent (almost like little glassy water spots). I've tried waiting for an hour after I glue the pic to the magnet, slowly pressing down to release the air, switching marbles - what else can I do? It happens more times than not. I was able to get a couple marbles that look fine, but the rest had those dreaded translucent bubbles and are now considered failures. Any tips or secrets for a beginner on how to make a fool proof marble magnet with no air bubbles? Thanks so much.