The Lighthouse offers ten rules for making text legible:
- Text should be printed with the highest possible contrast. (Black and white is recommended, but colors can be effectively contrasted; see the Lighthouse's instructions for effective color contrast.
- Type color is important for achieving contrast.
- Point size: Type should be large.
- Leading, or spacing between lines of text, should be at least 25 to 30 percent of the point size.
- Avoid complicated, decorative or cursive fonts. Condensed fonts are less effective.
- A roman typeface, using upper and lower cases, is more readable than italics, oblique or condensed.
- Text with close letter spacing often presents difficulties for readers who are partially sighted.
- Extra-wide binding margins are especially helpful in bound material because it makes it easier to hold the volume flat.
- Paper with a glossy finish can lessen legibility because many people who are older or who have partial sight also have problems with glare.
- distinctive colors, sizes and formats on the covers can make it easier to find a book or other document that is buried among similar publications.
If you think about it, these rules make perfect sense, the more so if you're over forty and have begun to notice vision changes. The book cover above was the cover that the large-print book publisher put on Irene Fleming's first book, The Edge of Ruin. The lady's face is sort of pretty but the text is nearly illegible. I can't imagine anyone with low vision pulling this off the shelf. It's mighty hard for them to see.
Kate Gallison (Irene Fleming)