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Selecting Changeable Letter Size

Always make sure customers can read your letter copy. The right size letter is determined by the functions of a few things:

  1. The speed of the passer by that you would like to read your message
  2. How far away that person is as they pass by
  3. How much message is on the sign
  4. The length of the letter track line

Many factors impact your site and appropriate letter size. We can help you decide. These are a few standard suggestions:

Letter Size Traffic Speed Viewing Distance Feet
4 inch 25 to 35 MPH less than 200
6 inch 35 to 45 MPH less than 300
8 inch 45 to 55 MPH less than 400
10 inch 65 MPH+ less than 500

Test Letter Size

How much message will you have? If your messages are short and to the point then smaller letters could be fine. If your messages are longer, then larger letters will increase the speed of recognition of your message. Locate a sign in your area that contains about the same amount of copy you would use, on a street with the same speed limit, with the same basic distance to the viewers, and then measure the letters on that sign so you know exactly what size they are. Get into the flow of traffic and see how well you read the message. If you are trying to decide between 4 inch and 6 inch letters find one of each sign to compare the experience. Remember that regular customers tend to be looking for your message and can generally read smaller letters. New customers may need larger letters to pick up your message.

The length of the letter track line will also impact your decision. Each letter size and letter style takes up a different amount of space on a line of letter track. For example, a 5-foot line of letter track would hold about the following quantity of letters and spaces in the following letter sizes and styles:

Modern Style:

4 inch - 16 letters
6 inch - 12 letters
8 inch - 9 letters
10 inch - 7 letters

Condensed Style:

4 inch - 21 letters
6 inch - 15 letters
8 inch - 9 letters
10 inch - 9 letters

ADM Style:

4 inch - 14 letters
6 inch - 10 letters
8 inch - 7 letters
10 inch - 6 letters

A line of track should hold approximately 15 letters and spaces to be effective. For example, a track that is 5 feet long one could use any 4-inch letter style or 6-inch condensed style.