The neon sign is the classic among illuminated signs. The tubes can be bent into almost any shape, which is especially useful in small signs where the details are important. By using different gas mixtures, colorants and colored glass it is possible to create light of almost any color. The neon tubes can be placed on the surface of the sign - something that is only possible when using neon tubes - or under a protective acrylic sheet. Neon tubes are also used in art.