A tactile writing system invented by Louis Braille who was blind from childhood. Basic Braille is an alphabet created by a pattern of raised dots within a 2 x 3 grid. The dots are numbered 1 to 3 from the top left to bottom left then 4 to 6 top right to bottom right. Numbers are created by using the first 10 symbols of the alphabet (a to j) preceded by a symbol to indicate a number (imagine a backwards L). See the attached pdf for the alphabet (UK), numbers 1-9 & 0, 123 & 1000.

In printing Braille can be produced by embossing or by the use of an thick ink which when dry stays raised proud from the page.