HIJL: veil divided into squares by thicker threads.

DEFG: drawing surface divided into the same number of squares as in the veil. The points at which the image of the object intersects the squared grid are noted, and equivalent points are transcribed on to the squared drawing surface.

This illustration show how a painter utilizes the linear perspective in his work.

Daraughsman Drawing a Recumbent Woman. Durer, 1525. Woodcut illusion from The Teaching of Measurements. 7.5 x 21.5.

This illustration shows a man drawing a woman reclining on cushions. He uses an upright grid and draws on paper which has a corresponding grid division, a device invented in Italy in the 15^th century. The draughsman's eye has to be directed to his subject over the top of a rod.