What Is Backlit Signage? You might hear or see backlit signage called backlit display graphics or backlit lighting displays, and that is simply describing what this type of sign truly is. This style of signage is meant to be viewed with a light source shining through it or behind it. Backlit Letters Signs are also called halo lit signs, reverse lit channel letters signs. They can be used both indoors and outdoors. The face and sides are made of aluminum and the back is made of a translucent material, such as Lexan, to allow for light transmission.