My husband and I have been using Tervis Tumblers for about a year now. At first I was not sure I really liked them. They are not the best looking glasses, but they sure do a great job at keeping things hot and cold for a long period of time.
The first Tervis Tumblers were plain and clear. Now, there are many different types, colors, and designs to choose from. They all are made of hard, durable plastic. We have dropped our glasses many times and have never had any problems with cracking, breaking, or chipping. The design is always a double layer of the hard plastic with rings all the way up and down the glass. The tumblers with a design basically looks like a fabric patch trapped between the double layer of plastic.
I love how hot these tumblers keep my tea and coffee. The best thing about them though is how they keep your drinks ice cold with making your hands cold or getting them wet with condensation. These glasses are great to take on camping and beach vacations!