Umber

#6B4A2EFormula Fe₂O₃ + MnO₂Earliest recorded use Prehistoric

21 eras40 artists66 colors

The brown that made shadow possible. Umber is ochre with manganese in it, and that manganese does two things: it darkens the colour, and it makes the paint dry faster than anything else on the palette.

Origin

Umber is an iron oxide clay containing between five and twenty percent manganese dioxide, and the proportion determines how dark and how cool it is. The name is usually derived from Umbria, the Italian region, though it may equally come from the Latin umbra, shadow — the ambiguity is old and unresolved. The finest grade came from Cyprus, sold as Turkey umber and later as Cyprus umber, and is noticeably greener and more transparent than the Italian. Like ochre, roasting changes it: raw umber is a cool greenish brown, and burning it drives off the water to give burnt umber, warmer, redder and more transparent. Both forms are in constant use in this atlas — raw umber in fourteen eras, burnt umber in fifteen.

In art history

Umber becomes central to European painting with the shift to oil and to dark grounds. The Caravaggisti and the Spanish and Dutch seventeenth century are built on it: the deep, warm, transparent darkness behind a figure in Caravaggio, Ribera or Velázquez is umber glazed thin, and it works because it is dark without being black — a black shadow is a hole, an umber shadow has air in it. Rembrandt used it constantly, in the ground, in the underpainting and in the final glazes. It is also the standard imprimatura, the toned layer brushed over a white ground to kill its glare before painting begins, and the standard colour for the initial monochrome lay-in of a composition.

In the studio

Manganese is a powerful oxidation catalyst, which makes umber the fastest-drying pigment in oil by a wide margin — a raw umber passage can be dry in a day where a zinc white one takes weeks. This is why it is used for underpainting: it sets quickly enough to be worked over the following morning. It is also why it is dangerous used carelessly. Fat-over-lean discipline exists largely because of pigments like this: a fast-drying umber layer applied over a slow-drying layer will shrink and crack as the layer below continues to move, and much of the wide craquelure in seventeenth-century painting traces to exactly this. Umber is otherwise faultless — lightfast, inert, cheap and usable in every medium.

Afterlife

Still mined, still cheap, still on virtually every palette. The Cyprus deposits remain the standard for quality. Synthetic iron-oxide browns exist and are more uniform, but umber's manganese content is the whole point, and a synthetic brown that lacks it neither dries the same way nor produces the same transparent depth in a glaze.