Readability Guidelines

Readability Guide

How to create documents that are easy for all to read

Preamble:

Many Australians have difficulty reading or managing printed information. A print disability can be due to:

  • Vision impairment that makes reading difficult or impossible.
  • Physical impairment that makes handling printed material difficult.
  • Visual processing impairment like dyslexia that makes interpreting print difficult.

The number of Australians with print disabilities is rising, particularly as the population ages and the incidence of vision impairment increases.

The major causes of low vision for people who are older include macular degeneration (loss of central vision), glaucoma, diabetic retinopathy and cataracts. Reading problems as a result of these conditions include the dimming and blurring of text, the inability to see small print and difficulty in making eye movements crucial to reading.

While prescription spectacles, magnifiers and other devices, and training in reading techniques can be of some help for people with a print disability, there are certainly practical ways in which text can be made more legible.

Contrast: Text should be printed with the highest possible contrast. There is good evidence that for many older and partially sighted readers, light (white or yellow) letters on a dark (black) background are more readable than dark letters on a light background. However, the traditional dark text on light background may be aesthetically preferable and more cost effective.

Colour: The clearest colour combinations are black and white. Different colours may be important for aesthetic or other reasons, the use of different colours should be restricted for larger or highlighted text, such as headlines and titles. Maintain as high a contrast of light and dark as possible. A readable combination might be dark text on a light pastel background, while a less readable choice could be pink on a blue background.

Type: This should be large, at least 12 point, though the relationship between readability and point size varies somewhat with typefaces. For large print documents 18 point should be used (refer to Large Print Guidelines).

Spacing and Justification: Spacing between lines of text, should enhance the clarity of the text and not make it look too busy. Many people with mild print disabilities have difficulty finding the start of the next line while reading. Text should be justified to the left hand margin. Spaces between words should be consistent. Justifying left and right margins results in wide and variable spaces between words and should not be used.

Indented paragraphs: Indented paragraphs should be avoided. Indenting paragraphs may result in difficulty in finding the first word of the paragraph as the left margin is used to oreintate the reader.

Typeface: Ordinary typeface using upper and lower case is usually more readable than are some less frequently used styles such as italics, slanted, small caps or all caps. Italics should be avoided where possible as the slanting of the type may distort some characters depending on font type. This may reduce readability and ease of reading. Bold and underlined versions of any typeface are often more legible because the letters are thicker and less distorted. These versions are good to use when highlighting text.

Fonts: It is a good idea to avoid complicated, decorative fonts and instead use fonts with easily recognised characters. Some people find fonts such as Arial easier to read; Serifs add another dimension to the print, particularly when it is small. Sans serifs fonts, Helvetica, Swiss and Arial are generally acceptable if there is sufficient contrast.

Spacing: Text with close letter spacing can be particularly difficult for people with print disability, especially those with central visual-field defects. Where possible, spacing should be well spaced and not dense.

Margins: A wide binding margin is especially helpful in books and other bound material, because it makes it easier to hold the volume flat. Many visual aids, such as stand and video magnifiers are easiest to use on a flat surface.

Paper: A glossy finish can reduce legibility because many people with print disability have difficulty with glare and light reflecting off glossy paper. A matt stock is recommended.

Book series format: A print disability often makes it difficult to find a book or document that is buried among similar publications, for example sets of books and brochures whose members differ only in title or volume number. Use of distinctive colours, sizes and formats on the covers of such series can be especially helpful.

More Information

For more information please contact:

  • Tony Clark Manager, Business Development
  • Telephone (03) 9864 9702
  • Email: [email protected]
  • Jay Richards Manager, Accessible Information
  • Telephone (02) 9334 3556
  • Email: [email protected]

The National Information and Library Service (NILS) has been established to improve access to published information for Australians with a print disability. Services available from NILS include a lending library of audio and Braille books, an accessible format production capability and consulting in both web accessibility and accessibility of published information. NILS is a joint venture of Royal Victorian Institute for the Blind, Royal Blind Society NSW and Vision Australia Foundation.