The colours used in architectural and mechanical drawings vary according to circumstances. Some draughtsmen use a very pale sepia for York stone in elevation, pale Payne's grey for Portland or Bath stone, pale indigo with ink dots lor granite, and darker tints of the same colours for the sections. This, it must be remembered, is chiefly in connection with London stock bricks. Architects, who ought as a body to have an eye for colour, are sometimes great offenders by using harsh and unnecessary colours on their drawings. An extreme case has been noted where a wrought-iron girder resting upon a cast-iron column standing on a stone base were all coloured bright Prussian blue. Blue in some form or other is much used by architects to represent stone, but it should be used very sparingly, so as to resemble the natural tint of the stone rather than the conventional representation. For a red sandstone, a pale tint of light red, Indian red, Venetian red, or burnt ochre might be used, depending upon the general elevation colour. For cement in any form in elevations, pale Indian ink or pale Payne's grey is generally used, with or without dots and markings. Windows may be coloured with black Indian ink, or washed Prussian blue, Prussiau green, or Payne's grey, according to circumstances.

A plain tint all over is the simplest, but a good artistic effect may be obtained with the exercise of a little skill.