Etched Glass
Sand blasted glass is popular in store front windows and door ways of restaurants. It is used to apply a logo or name of a business to the glass. This etching creates the look of a soft frosting, cutting into the surface, creating the illusion of dimension. Here is a great company to buy supplies for doing it yourself, Etchmaster. On the site there is a detailed description of how it works.
Etching is also used on flashed pieces of glass for stained glass windows. In flashed glass, two colors of glass are formed on top of each other. With etching, it is possible to remove one of the layers, exposing the second. This achieves two colors of glass in one piece without having to use colored paint.

