After reading your note, I searched Google for what you are looking for. This might be helpful to you: http://www.ceramictilepro.com/Tile-&-Grout-Sealer.php - you don't mention if the tile you have is glazed or not. but in any regard, the link I furnished says it's okay to seal the tile too, although it doesn't need to be sealed. Many years ago, I helped my dad, he was a Ceramic Tile Setter. I do recall working with a sealer that we covered even the glazed tile surfaces along with the grout and had very good results. That was way back in the late 1940's and early 1950's - a long, long time ago.