“French Cassel Earth, NB8, bituminous earth also goes by the names Cologne Earth or Van Dyke Brown. In comparison to our Van Dyke Brown, our French Cassel Earth is much less a violet warm brown and has a unique cool quality that brings it closer to black than brown. It does appear similar to asphaltum or bitumen in that it appears black with brown undertones. The texture and sheen of French Cassel Earth is both dry and tarlike at the same time. Cassel Earth is a naturally slow drier and tints to a warm and subtle gray. It is not a strong mixer but does impart a warm glow when used in place of black. Only moderate in lightfastness, we recommend a final, UV protective varnish for maximum durability.” -Just Paint 2012 -Williamsburg. Unfortunately this color was discontinued in 2020. “French Cassel Earth will also be discontinued. It is made with a natural, tar-like material called Bituminous Earth – NBr8, which is no longer available. This is the same pigment we have used to make our Van Dyke Brown. Although Williamsburg’s Van Dyke Brown will no longer be manufactured with Bituminous Earth, we have decided that because of its historical significance and important color space, we will keep the name but use alternative pigments moving forward. Van Dyke Brown will remain in the Williamsburg family of colors, but it will now be made with PBk9 Ivory Black and PR101 Synthetic Transparent Red Iron Oxide. Finding a blend to replace our Van Dyke Brown was a challenge, as Bituminous Earth is a very unique pigment. When it is milled in oil, it maintains a coarse feel and when painted from the tube in full masstone, catches light on a textured surface to produce a dark, rich, dusty brown. It has a warm, semi-transparent brown undertone that when drawn thin, shows the coarseness of the pigment. It also has extremely weak tinting strength and although brown in every other way, tints with white to a fairly neutral gray. Together these characteristics are somewhat contradictory, which we did not find possible to replicate using other pigments. In the end, we decided that the dark, blackish-brown masstone and translucent brown undertone were the most important characteristics to maintain with as neutral a tint as possible. We came to settle on a semi-opaque, warm black, with tinting qualities similar to a brown umber. We thought this would be a useful color for artists looking for an alternative to the traditional blacks who want to create deep brownish glazes and warm grays. In the new mixture, Ivory Black provides a dark base with some translucence. Transparent Red Iron Oxide has a reddish-brown color with a luminous undertone. This PR101 is the same pigment we use for our Dutch Brown (Transparent), which is a coarse color. For this blend we mill the pigment clusters to a smoother consistency. The new Van Dyke Brown is darker, browner, smoother and stronger than the old formula. You will notice tubes with the new formula labeled with the words “pigment change” under the color name to differentiate it from the old formula. It is a series 1 color and has a lightfastness rating of 1, which is excellent.” - Just Paint, Feb 2020. See https://justpaint.org/changes-to-williamsburg-van-dyke-brown-french-cassel-earth-and-french-noir-indien/ for more details as well as pictures comparing the old and new formulations. These comparisons are about Van Dyck Brown, which was discontinued, and contained Bituminous Earth also, so they may be of some value when trying to understand how the old French Cassel Earth compares with the new replacement paints. The pigment used in their French Cassel Earth was also in the old version of Van Dyke Brown.