Following the basic design guidelines listed below can help you create overhead visuals that are easily read by people of many different ages and abilities to read and see. Large print and well-organized visual aids are particularly helpful for some students with disabilities that affect their sight, learning, or hearing.
- Use a large font size, perhaps 36-point or larger. Be sure that the projected text can be read by most people sitting in the back of the room in which you are projecting.
- Use a font style like Roman serif or sans serif, which tend to have more space between letters than other font styles.
- Use boldface.
- Use italics and underlining for emphasis, but avoid using many different font styles on the same visual.
- Keep your visuals simple. Minimize the amount of text on each visual. Focus on just the main points of one topic on a single visual. There should generally be no more than about six words per line and ten lines per visual. In most cases, the minimum spacing between lines should be 1.5 times the word height.
- Use adequate contrast between text, diagrams, and pictures and background. Colors such as yellow and some greens and pinks do not show up well on overheads. Light or white letters printed on a dark background are more readable than dark letters on a white background.