linear perspectiveThis step-by-step demonstration of drawing proportions shows how using a plumb line can help keep lines at the right angles.

Plumb lines in art

In art, plumb lines are undeviating vertical lines used as a reference when determining alignment. They are often used in drawing the human figure.

This can be achieved by hanging a piece of wire or string from the ceiling so that it produces a line in front of your subject, as demonstrated at left.

See also: How to draw people