Apart from graphical elements (lines, arcs, circles etc.) technical drawings will also contain written information. These written informations are referred as “lettering”. Styles of lettering: Many styles of lettering are in use to day. However, a few styles which are commonly used are shown in given figure.

Standard heights/Width: The standard heights recommended by BIS SP: 46-2003 are in the progressive ratio of “square root 2”. They are namely 2.5 – 3.5 – 5 – 7 – 10 – 14 and 20 mm. The height of lower case letter (without tail or stem) are 2.5, 3.5, 5, 7, 10 and 14 mm.

There are two standard ratios for the line thickness “d”. They are A & B. In A = line thickness (d) is h/14 and in B=line thickness (d) is h/10.

Lowercase means small letters, as opposed to capital letters. The word yes, is for example, is in lowercase, while the word YES is in upper case. For many programmes, this distinction is very important. Programmes that distinguish between uppercase and lowercase is said to be case sensitive.