Van Dyke brown is a transparent pigment in use since the late 16th century. Originating from Kassel in Germany, it was originally called Cassel earth or Cologne earth. When
Sir Anthony Van Dyke (b.1599 - d.1641) emerged from
Rubens' shadows, he became
King James' I court painter. The extensive use of this brown pigment in his paintings marked a change in the colorant's history and it was called
Van Dyke brown ever since.
The pigment is mainly composed of organic (humic) substances deriving from peat, soil, or impure lignite - brown coal. The earth was mined, then dried thoroughly and crushed to obtain homogeneous granules.
The final paint has a high oil content and therefore a low lightfastness i.e. a low resistance to colour fading. Since the original Van Dyke brown resulted in an inferior paint film, painters of the 18th and 19th century used this earth colour to make their oil paintings look older and more authentic, hoping to increase the value of the finished product.
The commercial Van Dyke browns available nowadays are a far cry from the original pigment, being completely lightfast and somewhat closer to a warm black. Tendency for the paint to crack is still high however, and mixtures of transparent oxides are usually recommended.