Bone black
Charred bone, ground fine. Warmer and browner than soot, and less absolutely black, bone black is the black most European painters actually reached for — and the name on the tube, ivory black, is a historical fiction that has outlived the material it referred to.
Origin
Animal bone is heated in a sealed container without air until the organic matter carbonises, leaving carbon distributed through a matrix of calcium phosphate. The result is roughly ten percent carbon and ninety percent mineral, which is why it is less intensely black than pure soot and why it has a distinct brownish, slightly warm cast. Genuine ivory black was made the same way from ivory waste and was finer, deeper and more expensive; it has not been produced from ivory for well over a century, and every tube sold as ivory black today contains bone black. The name persists because painters know it and because no manufacturer wants to be the one who changes it.
In art history
Bone black is the warm black of European oil painting, used in eight eras here and countless individual pictures. Where lamp black cools a mixture, bone black keeps it warm, which makes it the better black for flesh shadows, for dark drapery that must not turn blue, and for the deep transparent darks of Baroque painting. Rembrandt, Velázquez and the entire seventeenth century used it heavily. It is also traditionally the black of the dark ground — the reddish-brown or near-black priming over which Caravaggio and his followers built figures out of light — and the black of most engraved and etched printing where a warmer tone was wanted.
In the studio
It is transparent in oil, more so than lamp black, which is precisely why it glazes so well: a thin bone black glaze deepens a shadow without closing it. It is completely permanent and inert. Like all carbon blacks it dries slowly, though the calcium phosphate content makes it marginally better behaved than lamp black, and it handles more agreeably, with more body and less greasiness. The one significant caution concerns very old preparations that were incompletely charred, which retain organic material and can, rarely, cause discolouration; modern manufacture does not have this problem.
Afterlife
Still made, still cheap, still standard. Its main modern competitor is Mars black, a synthetic iron oxide introduced in the twentieth century, which is opaque, powerfully tinting, fast-drying and completely reliable — everything bone black is not — and which has largely taken over in acrylic painting, where it appears in the later eras of this atlas. Painters in oil generally keep the old one anyway, because opacity is not what a shadow wants.
Where it appears
Every era and artist in this atlas whose palette includes this pigment.