Foreshortening is the point at which most people decide they cannot draw. A limb coming toward the viewer occupies almost no length on the page and a great deal of width, and everything a person knows about the shape of an arm fights against drawing it that way. The result is arms that are subtly too long, in almost every drawing, by almost everybody.

The problem is not observation. People see it correctly and draw something else, because knowledge overrides perception. The solutions are therefore techniques for outmanoeuvring your own knowledge rather than for looking harder.

We draw what we know

An arm is known to be a certain length, and that knowledge asserts itself the moment the pencil moves. This is a well-documented perceptual effect and it does not go away with experience; experienced artists simply have methods for working around it.

The first method is measurement. Comparing the foreshortened length against something else in the drawing, and trusting the comparison over your sense of what looks right, produces a correct result that will initially look wrong to you and correct to everybody else.

Overlap does what outline cannot

A foreshortened form has almost no informative outline, so the depth information has to come from somewhere else, and that somewhere is overlap. Where one form passes in front of another, an edge terminates, and each terminated edge tells the viewer which is nearer.

Drawing those overlaps explicitly is what makes a foreshortened limb read. Without them the shape is ambiguous, and adding shading to an ambiguous shape produces a rendered ambiguity rather than a resolved form.

Cross-contours carry the form

Lines wrapping around the form, even invisible ones sketched underneath, describe how it turns toward the viewer. They also make the drawing possible, because constructing a series of overlapping cross-sections is a tractable task in a way that drawing a foreshortened arm freehand is not.

This is the same construction argument made in the piece on drawing soft structure, and it applies more strongly here because there is so little other information available.

Exaggerate the compression

Accurate foreshortening frequently reads as timid, because the eye expects dramatic compression when it sees a form coming toward it. Pushing it slightly further than measurement suggests usually looks more correct, which is one of the few places where exaggeration improves accuracy of impression.

The safeguard is that overlap and cross-contour must remain honest. Exaggerated compression with correct construction reads as dynamic; exaggerated compression with vague construction reads as a mistake.

Boxes first

Reducing a limb to a box or a cylinder in perspective is what makes foreshortening learnable, because a box has visible planes and a cylinder has visible ends, and both can be drawn in perspective by rule rather than by feel. Building the organic form inside a constructed one removes almost all the difficulty.

Practising boxes at extreme angles, without any figure involved, transfers directly. It is dull and it is the fastest route through this particular obstacle for most people.

Foreshortening in intimate work

Close framing and two bodies in contact produce a great deal of foreshortening, often several forms at once, which compounds the overlap problem described in the piece on two figures moving together. Every limb still has to be traceable to an owner.

That makes construction non-optional in these scenes. A drawing that solves foreshortening by hiding the difficult limb has usually made a composition choice for the wrong reason, and it accumulates into the sameness of framing described elsewhere in these notes.

Lens choice changes the problem

How severe the foreshortening is depends on how close the implied camera is, which is a compositional decision rather than an accident. A wider implied lens produces dramatic compression and a longer one flattens it considerably, so a difficult drawing can sometimes be made straightforward by moving the viewer back, as described in the notes on focal length.

That is not avoidance if the choice is made for the picture. It becomes avoidance when every composition quietly ends up at the same comfortable distance, which is the framing sameness that accumulates whenever a technical weakness is being routed around rather than solved.

Getting past the hardest thing in drawing

Measure rather than trusting your sense of length, build boxes and cylinders in perspective, draw the overlaps explicitly, use cross-contours to turn the form, and exaggerate the compression a little. Then practise boxes at extreme angles until they are automatic.

Characters here are fictional and unmistakably adult, as set out in the reader agreement.