RAW UMBER DEEP
Chemical Description: Natural iron oxide, amorphous carbon
Pigment Number: PBr7 PBk7
Lightfastness Rating: ASTM I
Pigment Opacity: Semi-Transparent
Paint Opacity: Semi-Transparent
Raw Umber Deep is darker in shade than Raw Umber due to the addition of black to umber. This produces a colour similar to Bistre, a colour used by the old masters as the brown ink in their drawings. It was made by partially burning beechwood and then boiling the burnt wood to extract the colour, the watery colour result was used as ink.
Depending on the degree of burning of the wood the colour could be a yellowish brown but the most prized colour was a darker version much like Raw Umber Deep. Bistre ink can be seen in drawings from the Renaissance, in artists like Leonardo da Vinci, all the way through to the 19th century. Rembrandt’s ink drawings are particularly fine examples of the use of Bistre ink. While the name is still used, the original beechwood pigment production is limited to small-scale hand made and specialist production for the few artists who still use it.
Just as with the beauty of bistre ink in old master’s drawings, Raw Umber Deep can be a beautiful dark brown colour to use in a painting, especially for laying in dark tones for under painting at the beginning of a picture. A traditional way to start a portrait or figure painting was to start with a white priming base then paint a thin, transparent layer of an earthy colour over that. This very thin layer was called the imprimatura. Raw Umber was a good choice to do this for oil painters because Raw and Burnt Umber get their dark brown colour from manganese impurities and this manganese makes the paint dry faster. It was always best to have thin faster drying layers under thicker slower drying ones, a technique often called “fat over lean”. On top of this thin layer or imprimatura, the artist would then paint the dark tonal areas of the painting. Raw Umber was a good choice for this step as well, although it could also be done using blacks and grays (a technique called grisaille). This underpainting of the dark areas would still be done with thin paint, but not so thin as the imprimatura and therefore it would appear much darker against the lighter imprimatura background. These old master techniques fell out of favor in the 19th century because waiting for each layer to dry took a long time with oil paints. Acrylics, however dry very fast and it is possible to make several layers in a single day where the same layers would have taken weeks or months in oils. This makes experimentation with old master techniques a realistic proposition today despite a fast moving world, but only because of the technological advances that have lead to acrylic technology. With acrylics the speed of drying of individual pigments is not the major issue as it is in oils and so choosing colours other than Burnt or Raw Umber is feasible, however they are colours that work well with other fleshy colours and for that reason alone they are likely to be high on the list of choices for underpainting and imprimatura.
Apart from its use in under painting, Raw Umber Deep is an excellent colour for mixing with other colours to darken them and can be mixed with Phthalo Green and Matisse Rose Madder to make soft brownish blacks. It is a beautiful dark brown to use.
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