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APH Educational Research

Large Print: Guidelines for Optimal Readability and APHontTM a font for low vision

J. Elaine Kitchel
Research Scientist
American Printing House for the Blind

Introduction

Even though large print has been in use almost as long as the existence of the printing press, little has been done to bring large print to its full potential of usability by the low vision user. The American Printing House for the Blind (APH) has developed guidelines for its own use after a thorough study of current research and an examination of existing standards in the industry. It is hoped these guidelines will aid those producing large print documents to enhance the usefulness of large print for the reader.

Research evaluating the attributes of large print and their effects on reading speed and efficiency in persons with low vision is ongoing. For this reason, these guidelines must be considered dynamic and subject to expansion and revision.

Definition of Large Print

Large print is generally defined as print for text passages that is larger than the print used by that segment of the population with normal vision. The sizes of print most commonly used by the sighted population range from eight to twelve points in size. The American Printing House for the Blind takes the position that large print for use by the low vision population is print that is eighteen points in size or larger.

Example showing the x-height and the t-height in 100 point APHont. The 'x' in the word 'box' is the same size as the letter 'o' and the round part of the letter 'b'. The crossbar on the letter 't' in the word 'the' is the same height as the hump on the letter 'h' and the top of the letter 'e'

In addition to the size of the font itself, the x-height and t-height of a font can also be changed. (X-height is defined as the height of the letter "x" in any given font; t-height is defined as the height of the bottom of the crossbar of the letter "t" in any given font. Depending upon the font, t- and x-height may be different heights, or they may be the same.)

Other attributes that print designers are able to manipulate are: proportions, leading, spacing, character thickness, character edges, and character styles. These attributes could be manipulated either singly, or in combination, to maximize readability of a font. Line spacing and line length are other features of print that can be changed to guarantee good readability. APH has created a font, APHontTM, that embodies characteristics identified through research to promote readability in persons with low vision. APHont is available free-of-charge to qualified users from the APH web site.

Guidelines

APH's recommendations are based on replicated research performed by APH and other agencies. Researchers studied the impact of various large print characteristics on reading speed, comprehension, literacy, and usability by large print users and found subjects had better scores in all areas tested when using APHont.

These guidelines are outlined in the following statements:

Each large print user should have access to:

  1. A font that is at least 18 points in size.
  2. X-height and t-heights of at least 1/8 inch.
  3. A typeface without serifs.
  4. Spacing between lines of print of at least 1.25 spaces.
  5. Headings and subheadings that are larger and bolder than regular large print text.
  6. Paragraphs that are block style and use 1 inch margins. The left margin should be justified and the right hand margin should not be justified. There should be no first-line indentations to delineate paragraphs.
  7. Printed materials with no columns or divided words.
  8. Black print on white, ivory, cream, or yellow paper with a dull finish so as not to promote glare.
  9. Print that is not used over a background design or other graphical material.
  10. Graphics that are not only enlarged, but maintain the same contrast, clarity, and appropriate coloration as those prepared for their sighted peers.
  11. Graphic materials, such as maps, graphs, and charts, which also adhere to type size, font, and other large print guidelines. (Guidelines for maps are under development.)
  12. Full-color or high-quality black line art rather than gray-scale or shaded drawings.
  13. Books that weigh no more than 32 ounces and are no larger in dimension than 9 inches by 12 inches by 2.5 inches.

Summary

Research conducted by APH in the Student Survey of Large Print and Magnification Needs to Optimize Reading Efficiency, points to the validity and necessity of the above guidelines. APH believes these guidelines embody the attributes that have been shown through research to provide optimum readability for persons with low vision. APH is proud to lead the way in the development and implementation of these guidelines and will proceed with the sincere belief that persons with impaired vision will benefit from them. APH wants to keep a full range of options open for students who need textbooks. Producing high-quality large print that embodies features that have been proven helpful to persons who have low vision is one way to keep those options available.

References

  1. Arditi, A., Print legibility and partial sight. New York, NY: The Lighthouse Research Institute, 1992.
  2. Bailey, I. and Lueck, A., Magnification Needs to Optimize Reading Efficiency (unpublished study). Louisville, KY: American Printing House for the Blind, Draft (2001).
  3. Buultjens, M. Aitken, S., Ravenscroft, J. & Carey, K. "Size counts: the significance of size, font and style of print for readers with low vision sitting examinations." The British Journal of Visual Impairment. (1998) Edinburgh, Scotland.
  4. Carrol, T. J., Trautman, R. L., Collingwood, H. "Standards for production of reading material for the blind and visually handicapped." National Accreditation Council (1974) New York, NY: pp. 15-22.
  5. Gaster, L., Clark, C., (1995) "A guide to providing alternate formats." Center for Rehabilitation Technology Services (1995) West Columbia, SC: pp. 7-12.
  6. Kitchel, E., Evans, W., Student survey of large print (1999) Louisville, KY: American Printing House for the Blind: pp. 1-27.
  7. Mansfield, J. S., Legge, G. E., Bane, M. C. "Psychophysics of reading XV: font effects in normal and low vision." Investigative Ophthalmology & Visual Science 37 (8), 1492-1501. Draft (1996)
  8. Rubin, G.S. & Legge, G. E., "Psychophysics of reading: The role of contrast in reading". VII. Comprehension in normal and low vision VII. Clinical Vision Sciences, 4, (1989): 51-60.

APHontTM: A Font for Low Vision

APHontTM (pronounced Ay'-font), was developed by a licensed fontographer to specifications developed by APH. APHont was based on extensive research. It embodies characteristics that have been shown to enhance reading speed, literacy, comprehension, and usability for large print users.

Features:

Note: APH makes no claim that APHont is an appropriate font for children who are just learning to read.

How do I get APHont?

The complete APHont Suite with bold, italics, and diacritical marks containing both PC and Mac(R) versions of APHont is available by request only.

To download the new APHont Suite, fill out the online form at http://www.aph.org/products/aphont_orderform.html. You will be asked to verify that APHont will be utilized by or for persons with visual impairments. After verification you may proceed to download.

APHont(tm) Character Set

Examples of the upper case and lower case letters, numbers, and punctuation marks available for APHont Regular, APHont Italic, APHont Bold, and APHont Bold Italic
APH logo

©2004, American Printing House for the Blind, Inc.