1991 ADA Standards for Accessible Design

A4.30.4 Raised and Brailled Characters and Pictorial Symbol Signs (Pictograms). The standard dimensions for literary Braille are as follows:

Raised borders around signs containing raised characters may make them confusing to read unless the border is set far away from the characters. Accessible signage with descriptive materials about public buildings, monuments, and objects of cultural interest may not provide sufficiently detailed and meaningful information. Interpretive guides, audio tape devices, or other methods may be more effective in presenting such information.