Designing digital signage content: 10 rules for legible screens

A screen is neither a poster nor a website. It hangs further away, is seen in passing and keeps running without intervention. The content we get to see in consultations is almost always designed for the monitor on the desk, and there it looks good. On the device in the entrance little of that remains. These ten rules solve the most common problems.

Legibility: type, distance, contrast

Rule 1: Type size by viewing distance. As a rule of thumb, one centimetre of type height per 1.2 metres of distance allows comfortable reading. For a 55-inch display in Full HD that gives:

Rule 2: Contrast. Light text on a dark background or vice versa, at a ratio of at least 4.5 to 1 as with accessible websites. Grey on white and yellow on white vanish completely in daylight.

Rule 3: At most 20 words per frame. A headline, a sentence, a call to action. Anything that needs more text belongs on the website or in conversation, the QR code leads there.

Movement and duration

Rule 4: Animation sparingly. Movement draws the eye; too much of it drives it away. One element per frame may move, the text stays still. Tickers are barely legible from two metres and look like a news crawl from the nineties.

Rule 5: Duration per frame: 8 to 12 seconds for text, 5 to 8 for pure images. Shorter and people waiting cannot read; longer and the screen looks frozen.

Rule 6: Match the loop length to the dwell time. In the shop window 30 to 60 seconds, in the waiting room 8 to 12 minutes, in the canteen half the lunch break.

Format and imagery

Rule 7: Design for the target format. Portrait is not rotated landscape; layout, crop and text flow change. We set up every template in both formats.

Rule 8: Photos at full resolution, no screenshots, no graphics from the phone. An image of 1920 by 1080 pixels for Full HD, 3840 by 2160 for 4K. Blurred logos are the detail we correct most often.

Automation and brand

Rule 9: Data feeds instead of manual work. Weather, time, opening hours, menu of the day, waiting times, news, social media posts and calendar can be integrated as feeds and update themselves. A screen that stays current without maintenance survives everyday life, one that shows last month's weekly offers does harm.

Rule 10: Cast the corporate design into templates. Colours, fonts, logo position and image style are set up once as a template; the team then only fills in text and image. That way the presence stays consistent even if three people maintain content.

The practical test before going live

Stand with the finished frame on the device at the distance your customers actually have and read aloud. What you cannot take in within three seconds gets cut. Second test: look at the screen in daylight, not in the evening in the office. Third test: ask someone who does not know the content what they saw.

Conclusion

Large type, high contrast, little text, calm movement, fixed templates and as much automation as possible. That way content works on every screen. We build templates in our clients' corporate design and integrate data feeds; we do the distance test right there on your premises.

More on this: digital signage software and graphic design.