In Large Print Access to printed information for millions of people with low-vision is significantly restricted because printed information is not readable. Readability of printed material may be defined in terms of those characteristics that determine speed, accuracy and ease with which it may be read. The size type affects readability.
Type is measured by measuring a captial letter from the baseline to the top of the cap.
Type an inch tall is equal to 72 points. Most books are set to 10 or 12 point type, newspapers and toolnotes are often 8 point. Large print materials are most commonly available in 16 or 18 point type. Ask the user about the size of type required. Many people need 28 to 36 point type.