The following information may help determine what size of letters you should use on your sign given the viewing distance. A common mistake is not consider how quickly a sign can be read. Building Signs are frequently undersized with traffic flow and speed. Shopping Center Signs have two viewing areas. One from the main street and one from slow moving parking lot traffic. Wall signs are many times restricted by the landlord or municipal sign code on how large they can be. Illuminated letters need to be at least eight inches tall to be practical for fabrication. Viewing Distance at 100′ needs a minumum letter height of 4″. 250 feet = 10″
360 feet or about a city block = 16″
500 feet = 22″
If you get to about one quarter of a mile about 57″ is minimum size.
Make sure your letter has enough contrast to the background to be visible. Sometimes a border around the letter will help. For example, a white letter with black trim would offer a nice contrast.
