Hello! I use a color laser printer and print them off on laser labels and then mount them on matte board. That way I dont have to worry about warping and the toner gives the tiles a slight waterproofing. I've also seen it done successfully with ink jet printers and chipboard (thickness of cereal boxes) and what Stormboy suggested is a good method also. It just depends on how thick you want them and what you have access to.