Safety Sign Message Viewing Distance

ANSI Z535-2002 standard uses a ratio of 25 feet of viewing distance per inch of text for FAVORABLE READING CONDITIONS, and a ratio of 12 Feet of viewing distance per inch for UNFAVORABLE READING CONDITIONS.

Determining the safe viewing distance of a sign depends upon many factors, including lighting, background, letter type an visual acuity. Other factors to consider in determining label size, include: the complexity of the message, the reaction time necessary, and the angle the sign will be seen from. In many situations it is better to use multiple smaller signs that are strategically positioned instead of one large sign.

Many times letter size may need to be larger than the values shown on the graphic for a variety of reasons:

1. To make the label more noticeable from other information displayed in the area
2. To enable legibility under low light, or other poor viewing conditions
3. To alert persons sooner than the minimum safe viewing distance
4. To convey special importance for portions of the message
5. To improve legibility for persons who have vision problems with small text