Uncontracted Braille
Braille was developed in 1825 by the Frenchman Louis Braille. It is read using one's fingers. With up to six dots, which form a cell, all the letters of the alphabet and a few other sounds (ch, th, ed...) are represented in various arrangements. The patterns must be large enough to be felt with the fingers. The paper used is stiffer than typing paper in order to ensure that the dots are not easily flattened out when pressed. That and the size of the characters are the reason why books written in braille tend to be much thicker than conventional books.
Contracted Braille
Contracted braille works with patterns for common syllables and word stems. This allows texts to be shortened to 60% of the length of a text in uncontracted braille.
8-dot-braille
In order to reproduce each letter clearly when working with a computer, the introduction of braille with patterns made of up to 8 dots each was necessary. It is also called Euro-braille or computer braille.
Writing devices
The simplest device, which not many writers use today, is a slate and stylus. Each dot is punched individually into the sheet in reverse order. To read the pattern you turn round the sheet.
A braillewriter makes it possible to write one complete pattern at a time by means of simultaneous pressing of several keys. You can immediately check what you have written.
A computer workstation for a blind person is equipped with a braille display, on which the writer is able to read with his/her fingers what a sighted person would see on the screen.