Hoover Raw Umbers are naturally occurring Iron Oxides, which can range in color from a deep brownish black to a cloudy coal black. As with all Iron Oxide Pigments Raw Umbers are permanent and light fast. They possess limited heat resistance and excellent chemical resistance. Burnt Umber can be used as a transparent pigment and often used to produce greenish-brown colored furniture finishes. Their neutral tones also often find use in colorant systems. Hoover offers a variety of eight standard Raw Umbers.