The bowling ball is covered with mosaic mirror tiles! I made this gazing ball in the summer of 1999. It has been outside all this time and is still in perfect condition. Considering the extreme weather conditions in Wisconsin, this is pretty fantastic! I used Liquid Nails Silicone Sealer for the glue. The bowling ball was purchased at a nearby Goodwill store for $3.50. I used some small pieces of tin cut in circles and glued over the top of the fingerholes to seal them up. The butterflies were drawn on a piece of typing paper and transferred to the ball with sewing carbon paper. I then went over the design with a permanent marking pen. The ball was blue so the lines showed up great. 1/2" squares of various colors of mirror were cut into chips and glued into the design areas. I did use several larger pieces of the mirror for the butterfly bodies. The background is made up of regular 1/2" square mirror tiles. I did have to trim many pieces to get the design to flow around the butterflies, but you really can't even tell which ones were cut. This was the first ball I did. I will definately be making more.