The newest trend in cell phone accessories are skins and design covers. They are made of hard plastic or in the newer market adhesive-backed vinyl pieces. These vinyl skins can be ordered on many websites and come pre-cut to fit your cell phone or even another electronic device. There exist two different types of vinyl material, calendared or cast, with the latter being more expensive. In short, calendared vinyl is expected to only be used for short durations while cast vinyl is used on a more long term basis. Calendared vinyl also tends to shrink in the heat, and fade in color. On the other hand, cast vinyl can cure all of these problems, yet costs up to 250% more (which still is a very cheap total cost). While the technology of these adhesive-backed skins continues to improve, the most up to date technology comes from 3M. The company has manufactured a cast vinyl product that they call "Controltac". This vinyl cover maintains a more glossy look and provides an air release channel that prevents bubbles during placement. The more popular is the cast vinyl because of the range of designs. There are even some which are 3D.