1. Cut the clear mounting sheet to the size you need for your backsplash. (We used Mosaic Mount, available at craft stores or stained glass suppliers. It is a flexible transparent sheet that sits on the face of the tile as you install it and is removed after the tile is set into place and the mastic has dried). Pieces larger than 12-inches square are hard to handle once the nuggets are attached, so you may want to make your backsplash or border in several pieces.