For my projects I like to use non sanded grout for the base for a few layers and then sanded grout for the top few layers. Start real thin to get a good coating on everything and gradually get thicker and thicker. I normally do anywhere from 8 to 10 layers all together depending on the piece and font forget to do a bunch of layers of nontoxic sealant! I use Modge podge matte at first and finish with the modge podge hard coat. I generally do about 6 layers of sealant all together(3 layers of each) just to be on the safe side.