If pigments were drugs, asphalt would be cocaine – addictive and seriously destructive. Until the Impressionists tried to eliminate black from the palette altogether, numerous painters are claimed to have used asphalt in their oil paintings, and many paintings are claimed to have suffered its destructive consequences.

Except that very, very few paintings have actually been demonstrated to have contained asphalt as a pigment at all.

Together, these make asphalt one of the most mysterious pigments. It was apparently used by many Masters, including Titian, Rembrandt, Tintoretto, Velázquez, Reynolds, JMW Turner, David, Delacroix, Ingres, Courbet, Anton Mengs, Hans Makart, and many more. It was attributed the lustrous, rich brown-black which is so widely seen in their works. But very few of their paintings have been found to contain robust evidence of its use.

Asphalt isn’t even a true pigment (insoluble particles containing substances of intense colour), but an odd colloid cocktail of organic and inorganic materials. Some, such as the viscous binder within asphalt known as bitumen, are organic residues. Other components can include modified vegetable matter, mineral particles, and more. Asphalt and its derivatives also go under a variety of names, including Antwerp Brown, and possibly Mummy.

Mummy is even more mysterious than asphalt. Originally claimed to be extracted from the ground bodies of embalmed Egyptians, it was thought that asphalt formed an important part. Its origin and composition appear to have changed over time, and at some periods the pigment known as Mummy may well have contained significant amounts of asphalt.

Reliable tests for the presence of asphalt in paint are highly specialised, and little-used, and little is known about asphalt’s behaviour in oil paint layers. As a result, it is not clear when it first came into use, although most consider it was used during and after the Renaissance, and gradually phased out during the nineteenth century.

Asphalt has been used as an oil paint, and in varnishes; being strongly hydrophobic it is very poor in watercolour. It is not the ‘blackest black’ as has sometimes been claimed, but a very deep brown-black, which has been prized by many artists.

Notorious for the problems with which it can be associated in the paint layer, asphalt has been blamed for bleeding, discolouration, wrinkling, and cracking. But careful examination of paintings known to contain it suggests that those are not necessarily the consequences of using asphalt: genuine asphalt has been used in some old paintings without any of those ill-effects.

Orazio Gentileschi’s Joseph and Potiphar’s Wife painted in 1626-30 is one of the few paintings which is known to contain asphalt in its paint layer, yet appears in remarkably good condition, considering that it is nearly four hundred years old.

Another painting known to contain asphalt in its paint layer is Gerrit Dou’s The Young Mother from 1658. Most of the darks and blacks in the centre of the painting don’t show the brown tinting which is characteristic of asphalt, but I suspect it may be in the dark browns towards the top.

This detail reveals a different pattern of cracking in the dark brown drapery at the very top, which has open and coarser cracking than most of the rest of the painting. I wonder if that is consistent with some adverse effects of asphalt here.

One major work in which there appears to be extensive written evidence of the use of asphalt is Théodore Géricault’s The Raft of the Medusa (1818-19). However, critical examination of sources shows that they depend on a single original document, a note made on an unspecified date by Géricault’s assistant Jamar, who listed the pigments used by the Master as:
“vermillon, blanc, jaune de Naples, ocre jaune, terre d’Italie, ocre de Brie, terre de Sienne naturelle, brun rouge, terre de Sienne brûlée, laque ordinaire, bleu de Prusse, noir de pêche, noir d’ivoire, terre de Cassel, bitume.”

Cassel earth is a derivative of lignin rather than asphalt, but readily confused with asphalt as they have similar colours. Géricault is alleged to have used asphalt glazes or varnishes late in the painting process, but at that stage few witnesses were allowed access to the studio.

The Raft of the Medusa may well have undergone varnishing with asphalt, and is the worse for wear considering that it is only two hundred years old. However, its life has been very stressful: it remained unsold after its was first exhibited at the Salon in 1819, so was rolled up and stored in a friend’s studio, until it was transported (rolled up still) to London for exhibition the following year.

There are also claims made for several of JMW Turner’s paintings that they contain asphalt in the paint layer, which has resulted in their deterioration. I am not aware of any robust analyses which have confirmed its presence, though.

Turner’s Fighting Temeraire has areas in which wrinkling is apparent, probably resulting from the slumping of impasto, and undried paint exuding. This has been attributed to Turner’s assumed use of asphalt, which can inhibit the oxidative ‘drying’ of linseed oil.

The Rape of Proserpine (1839) also has its problems. Here Turner worked freely, mixing layers of low to medium impasto with thinner glazes and scumbles, particularly in the sky. Although cracking has occurred, this has not resulted in significant loss of the paint layer.

It has been proposed that problems in the foreground and middleground of Turner’s Rape of Proserpine are the result of his use of asphalt. Cracks here have widened, and become filled with paint which has risen from deeper layers.

Many of the paintings of the American artist Albert Pinkham Ryder (1847–1917) have suffered severe problems in the paint layer, and some are now almost completely lost as a result. Ryder was known to have incorporated a wide range of unconventional materials and substances in his paintings, which are thought to have included asphalt. Unfortunately, there does not appear to be robust analytical evidence to support his use of asphalt.

The Waste of Waters is Their Field (c 1883) is a small oil painting which is almost completely lost now, with much of the detail merged into a dark brown mess as its superficial layers have faded, and the deeper layers darkened. The detail below shows that its entire paint layer is dissected by cracks, many of them gaping and oozing lighter wet paint from below.

Details can still be made out in his tiny Resurrection (1885), although even this has changed and cracked severely. Many of the cracks are wide and filled with paint which has risen up from lower layers.

The objective evidence shows that it is quite possible for paintings containing asphalt to live long and strong, but its rumoured use has been claimed to result in destruction of the paint layer. Perhaps it is as well that asphalt and its relatives became unfashionable in the nineteenth century, and are almost unobtainable in oil paints today.

There are other deep brown-blacks, but none with the same air of mystery.

References

Géricault’s Raft of the Medusa, a detailed analysis of the evidence of its making.

Catarina I Bothe (2007) Artists’ Pigments, vol 4, ed Barbara H Berrie, Archetype. ISBN 978 1 904982 23 4.