Visibility Chart

Even if your letters are visible to you, if they can't be read by your intended audience they have little value. Letters that are too small to read are common.

Some things to keep in mind:

Finish & Color Contrast: Letters that blend in with their background become illegible at moderate distances. This applies to letters that may reflect a similar color as the sign background, or dark letters that may blend into a building brick or stone. Also, shiny letters will obviously contrast more with a dull background. The amount and type of lighting, both artificial and natural, is also important to overall legibility.

Negative Space: Simply enlarging letters does not always make them more readable. Proper letter spacing and spacing between lines of text have almost as much to do with legibility as size. Maintaining a certain degree of "white space" is important to keep the letters from running together or running into other distractions around the sign.