DotsPlus® Braille

Introduction to DotsPlus® Braille

DotsPlus® Braille is a set of tactile fonts that permits virtually any computer document written in a language based on the roman alphabet to be printed in a form readable by a blind person. Standard text printed in the six-dot DotsPlus® Braille font reads very much like grade 1 (uncontracted) standard braille. The eight-dot DotsPlus® Braille font set is identical except that most double cell characters of the six-dot fon are single cells in the eight-dot font. Capital letters in the eight-dot font for example are the familiar single cell letters of eight-dot computer braille. They have an extra dot (dot-7 position) on the left side of the row just below the bottom of the standard six-dot lower case letter cell.

Common punctuation marks are not braille but are small graphic symbols. Most feel like literary braille punctuation marks but, unlike braille punctuation, are distinguishable out of context from letters. The vast majority of characters that appear in more complex literature (math, science, computer programs, accents on foreign characters in English literature, etc.) are graphic symbols shaped much like the corresponding print symbols.

DotsPlus® Braille overcomes four problems that plague braille:

  1. Translation. Even grade 1 literary braille is a code, and any standard document must be translated into braille either by hand or by a computer to be readable in braille. DotsPlus® Braille font characters are simply substituted for the standard print characters.

  2. Numbers. Literary braille and the proposed unified braille code represent numbers by "number mode" - a device that cannot be used as a font and is very clumsy in advanced math/science. DotsPlus® Braille uses the single cell European computer braille numbers. Digits 1-9 are formed by adding an additional dot-6 to the letters that represent these digits in literary braille number mode. Zero (dot-346) is an exception, because of conflict with the letter w. Although DotsPlus® Braille numbers typically require several weeks of training to "feel right" to a braille reader, their close relationship to literary numbers makes them easy to remember from the beginning. DotsPlus® Braille numbers have no meaning in grade 1 (uncontracted) braille.

  3. Exotic symbols. Braille readers can usually learn and remember symbols that are common but have serious difficulty with less common symbols. These must be represented by multiple braille cells that few readers can remember. Uncommon DotsPlus® Braille symbols are tactile graphic symbols with shapes similar to the print ones, and the learning/remembering process should be very similar for blind and sighted readers.

  4. Symbols out of context. Braille is intrinsically a straight line notation. Isolated characters can be ambiguous. For example an isolated line composed of the letter c, the colon, or the dash are indistinguishable in braille. They are distinguishable in DotsPlus® Braille, leading to the ability to print math in standard print format, superscripted characters in standard text, and isolated symbols in any context in graphic applications.

The DotsPlus® Braille paradigm was proposed in the early 1990's, but it was not feasible to use it except for very limited purposes until the commercial introduction of Tiger embosser technology in 2000. The Tiger Tactile Graphics and Braille Embosser technology developed by the Science Access Project now provides the "missing link". TIGER technology permits documents to be prepared using standard computer applications and embossed for blind readers just as one prints a document on a standard printer for sighted readers.

Literary braille is fine for "plain text' but is difficult or unusable for more complex literature. Our hypothesis is that both blind readers and people who prepare materials for them will prefer DotsPlus® Braille over current tactile methods for most complex literature. Small scale tests conducted with Oregon middle, high school, and university student volunteers support this hypothesis. Funding for larger scale tests has not been available, but users of Tiger technology embossers can now "vote with their fingers".

Since none of the WorldWide Web clients are yet able to display raised images, a tactile example of DotsPlus® Braille and other Tiger samples can be obtained with the help of the U.S. PostalService by contacting

Last Updated January 22, 2005