A battered silver mask stares straight out of the frame, filling almost the whole square, its metal scarred and dented like something dragged off a battlefield. This is MF DOOM, and on the front of Madvillainy he is only a face of gladiator steel above a body that dissolves into black shadow.

The shot is grayscale, cool and clinical, a portrait stripped of any warmth except one intrusion: a small orange square parked in the top corner, the single spot of colour in an image otherwise built from silver, grey and darkness. Above the eyes, spaced thin capitals read DOOM AND MADLIB, and beneath them the group name lands in bold: MADVILLAIN.

The eyes behind the mask sit in shadow, giving away nothing. That was the point. In 2003 the rapper was a rumour more than a public figure, and the cover refuses to solve him. It shows a man who happens to be wearing a mask rather than a mask alone.

How that steel face got photographed, why the orange square exists at all, and what the man behind it thought when he first saw it are all stories in themselves.