This fun 20 oz. Polar Camel Tumbler with Silicone Grip and Clear Lid has a fun laser engraving on the silicone sleeve. Due to being handmade the colors of the sleeve may vary for each mug. Each design is made by Kristi's Keepsakes. Laser engraving is a process that vaporizes materials into fumes to engrave permanent, deep marks. The laser beam acts as a chisel, incising marks by removing layers from the surface of the material