I want to make coasters for the holidays. I was going to buy tiles at the local hardware store, but the smallest option (in a decent price range) is way too big for a coaster. While at the local craft store I found paper/cardboard coasters that will work, but I'm wondering how to completely waterproof them (heat proof would be nice too). Any ideas? Thanks in advance.
You need to polyurethane them. Paint it on and let it dry. Sand lightly, then repeat this step at least 3 times. They will come out really smooth, like glass, it is the same way you would do a piece of wood.