Post by Glen Coard - PacBlue’s Signage Expert.
It’s one thing to design & build your signage with flair, but without proper legibility, your efforts may go unnoticed.
Most Out-of-Home-Advertising (billboards, for example), are read from a substantial distance (“50 meters at 50 kph”, I like to say), so your exposure time, and advertising impressions (CPM) can fade into the distance along with your marketing return. See my illustration for Distance Readability.
In addition to Distance Readability, designers should also regard Exposure Time:
Consider you are driving on a highway at a speed of 100kph, which means you are traveling at about 27 meters per second. If you want 5 seconds of exposure, then your sign will need to be readable from a distance of 135 meters.
According to the table below, the smallest letter should be about 16 inches tall. (f the driver chooses to read your secondary copy, s/he will be closer in a few seconds and the smaller copy will become readable).
OFFER to my LinkedIn friends:
If you don’t want to bother with my conversion calculations, I’d be happy to prepare and email you a quick Readability Illustration (like the sketch attached) for your project. It’s no problem, (and won’t cost a dime). Not limited to signage, my same readability principles can be used for other projects, such as real estate, landscaping, construction, outdoor marketing, sporting venues, safety markings, vehicle signage, or just about anything that requires distance viewing consideration.

IMPERIAL
Distance from signage: Minimum readable: Readability with Impact
100 ft. 4 inch letters 12 inch letters
200 ft. 8 inch letters 24 inch letters
300 ft. 12 inch letters 36 inch letters
400 ft. 16 inch letters 48 inch letters
600 ft. 24 inch letters 72 inch letters
METRIC (approx)
Distance from signage: Minimum readable: Readability with Impact
30 meters 10 centimeters 30 centimeters
60 meters 20 centimeters 60 centimeters
90 meters 30 centimeters 90 centimeters
120 meters 40 centimeters 120 centimeters
180 meters 60 centimeters 180 centimeters
About Glen Coard:
Glen Coard is a printing & signage industry veteran who has over 30 years of experience. Specializing in customer relations, troubleshooting, production and technical knowledge Glen is always ready to help when needed.
With over 5 years with PacBlue Printing Glen is your point of contact for any related question on our signage solutions. Send your questions to: sales@pacblueprinting.com