Color Swatch created using full strength/50/50 and was applied on cold press Bristol board (2 ply) material.
This color contains the following pigments:
PBr7—Raw Umber
Pigment Type
earth
Chemical Name
hydrated iron oxide
Chemical Formula
α-FeO3+(OH) or Fe2O3 × MnO2
Properties
Raw Umber is a cool, transparent brown ranging from yellowish brown to greenish brown. It has surprisingly good tinting strength, a high level of opacity, mixes well with greens, and is quick drying in oil form. It has excellent color properties and can create a variety of subtle, clear tints when mixed with white. It grays when mixed with blue and white. Raw Umber can tend towards chalkiness in dark mixes in oil form.
Permanence
Raw Umber has excellent permanence.
Toxicity
Raw Umber itself is considered non-toxic. If contaminated by manganese compounds, it may be highly toxic if inhaled and moderately toxic if ingested.
History
This pigment gets its name from the Latin word umbra, meaning shadow or shade. Its full name is listed as terra di ombra, meaning earth of shadow/shade, due to its original extraction from the area of Umbria, Italy. It has been used as a pigment since prehistoric times. Currently, the finest umber comes from Cyprus.
Alternate Names
Chestnut Brown, Euchrome, Jacaranta Brown, Mars Brown, Raw Brown, Sicilian Brown. Cyprus Umber, Turkey Brown, and Turkey Umber are the best quality umbers.
NBk6—Asphaltum
Pigment Type
inorganic
Chemical Name
n/a
Chemical Formula
n/a
Properties
Asphaltum is a transparent black pigment with low tinting strength. It is often used as a glazing black.
Permanence
In high concentrations it interferes with drying and bleeds into other colors. It is prone to decomposition when exposed to sunlight.
Toxicity
Asphaltum is non-toxic and non-carcinogenic.
History
Asphaltum is a natural hydrocarbon mineral. Although it is found in mineral deposits, it is more often produced synthetically as a residue from petroleum processing or as a distillate from coal gases. Naturally occurring deposits of asphaltum have been used since prehistoric times for waterproofing. It has been used as a pigment since at least the 16th century, and probably much earlier.
Alternate Names
Gilsonite, Antwerp brown, natural bitumen
