Bob Ross Oil Color - Mountain Mix, 6.8 oz tube

Pigment Information

This color contains the following pigments:

PB27-Hooker’s Green

PBr7-Burnt Sienna

PBk9-Ivory Black

PR83-Alizarin Crimson

PG7-Phthalo Green

Pigment Name

PB27-Hooker’s Green

Pigment Type

mix of organic pigments

Chemical Formula

C30H18FeN3O6Na

Properties

Hooker’s Green is a bright olive-green often sold in a yellowish shade and a bluish shade. Its transparency can range from dull and dark to bright and light because lightness and chroma vary based on manufacturer. Modern varieties have a rich, dark tone that provides a great range when mixing. Hooker’s Green is particularly good for landscape painting when a larger range of foliage is required. Dioxazine Violet is the best mixing compliment in watercolor form.

Permanence

The permanence and lightfastness of Hooker’s Green varies by brand. As a composite pigment historically mixed from Prussian Blue and Gamboge, its permanence is only fair. Modern replacements for Hooker's Green tend to be mixed with components that have more permanence, such as Phthalocyanine Green, Burnt Umber, and sometimes Hansa or Cobalt Yellow.

Toxicity

Hooker’s Green can be hazardous, but the toxicity level depends on the specific pigments used by each individual manufacturer or brand.

History

This pigment was originally an unreliable mix of Prussian or Iron Blue and Gamboge. Later, it became a more reliable mix of Cadmium Yellow and Phthalo Blue or Green. It was a staple green for 19th century landscape and botanical painters. Most modern Hooker’s Green paints are yellow greens with a hue angle around 140, or a mix of Phthalo Green and Burnt Umber.

Pigment Name

PBr7-Burnt Sienna

Pigment Type

earth

Chemical Name

iron oxides

Chemical Formula

Fe2O3

Properties

Burnt Sienna is a warm, mid-brown color formed by burning the yellow-brown limonite clay called Raw Sienna. It ranges from semi-opaque to semi-transparent due to the combination of its opaque, red-brown mass tone and its transparent, orangey undertone. It is an excellent mixing complement for blues and greens and creates salmon or peach colored tints when mixed with white. It can be useful for subduing bright colors and does not get chalky in dark mixtures.

Permanence

Burnt Sienna has good permanence and is considered one of the most versatile of the permanent pigments.

Toxicity

Burnt Sienna has no significant hazards.

History

Burnt Sienna has been used as a pigment since prehistoric times, but its current name came about during the Renaissance. It comes from the city of Siena, in Italy, and is short for terra di Siena, meaning earth of Siena. Sienna was famous for the mining and production of earth pigments from the Renaissance until World War II. Due to the depletion of clay deposits in Tuscany, Italian siennas now come from other areas, including Sicily and Sardinia.

Pigment Name

PBk9-Ivory Black

Pigment Type

charred animal bone

Chemical Name

carbon + calcium phosphate

Chemical Formula

C + Ca3(PO4)2 or C x CaPO4

Properties

Ivory Black is a cool, semi-transparent blue-black with a slight brownish undertone and average tinting strength. It mixes well with any color, and creates a range of dull greens when mixed with yellow. It has good properties for use in oil, can be slow to dry in oil form, and should never be used in underpainting or frescoing. Ivory Black is denser than Lamp Black.

Permanence

Ivory Black is very lightfast and has good permanence, though it is considered the least permanent of the major black pigments.

Toxicity

Ivory Black has no significant hazards.

History

Ivory Black is a carbon based black first named as Elephantium, and described in the 4th century BCE as produced by heating ivory scraps in clay pots to reduce the ivory or bone to charcoal. The deviation in names is because the more expensive varieties of this pigment were made by burning ivory, and the less expensive ones by burning animal bone. In the 19th century, the name Ivory Black was finally permitted to be applied to Carbon Black pigments made from bone. True Ivory Black is rare in modern times due to the protection of ivory, and the synthetic variety produced today was discovered in 1929. Bone Black is produced as an industrial pigment.

Pigment Name

PR83-Alizarin Crimson

Pigment Type

organic

Chemical Name

1,2-dihydroxyantraquinone

Chemical Formula

C14H8O4

Properties

Alizarin Crimson, the traditional cool counterpart to Cadmium Red, is a clear ruby-red with a maroon masstone and a bluish undertone. It is the artist's principal deep red pigment, is transparent, and has good tinting strength. It creates bright rosy pinks when mixed with white, a range of purples and violets when mixed with strong blues, can be slow drying when used with oils, and is compatible with all other pigments. Permanent Alizarin Crimson mixes well with Ultramarine in acrylic and watercolor form. Permanent Rose and Quinacridone Rose are possible alternatives on a watercolor palette. Alizarin Crimson is a popular glazing color.

Permanence

Alizarin Crimson is considered fugitive or marginally lightfast, and the appropriateness of its use in the modern artist palette is a subject of debate. There are many concerns regarding its permanence, particularly when mixed with ochre, sienna, and umber, or when used thinly. It is the least permanent red commonly used by today's artists. Modern synthetic preparations of Alizarin Crimson have better permanence and lightfastness that the original natural pigment, which was extracted from the madder plant. Quinacridone pigments have been used to create a modern hue that closely matches the original hue, but many artists object that the transparency and handling characteristics are not the same as for the original.

Toxicity

Alizarin Crimson can be slightly toxic if it comes into contact with skin and may cause some allergies. There is no significant acute toxicity.

History

The word alizarin comes from the Arabic word al-usara, meaning juice. The base ingredient of this pigment is the Madder plant (Rubia Tinctorum). It was used for dyes and inks among craftsmen in Ancient Persia, India, and Egypt as early as 1500 BC In 1804, George Field, an English dye maker, developed Madder Lake by binding madder to alum, a white powder. The German chemists Carl Grabe and Carl Liebermann produced the first synthetic variety of this pigment, most commonly known as Alizarin Crimson, in 1868. They used anthracene, which greatly improved the lightfastness. The Colour Index International designation PR83:1 has been used to identify this synthetic laked pigment.

Pigment Name

PG7-Phthalo Green

Pigment Type

organic

Chemical Name

polychlorinated copper(II) phthalocyanine

Chemical Formula

C32H3Cl13CuN8 to C32HCl15CuN8 or C32H16CuN8Cl15 (PG7) or C32Br6Cl10CuN8 (PG36)

Properties

Phthalo Green is a transparent, cool, bright, high intensity color used in oil and acrylics. It comes from a Phthalocyanine Blue pigment where most of the hydrogen atoms have been replaced with chlorine, forming highly stable molecules. It has similar pigment properties and permanence to Phthalo Blue. It is slow drying and an excellent base color for mixing a range of bright greens. Phthalo Green is considered a very good alternative to Viridian because it is intense and mixes well and can be used to emphasize mineral colors in various tints. However, its tinting strength is very high, so it can overpower other colors. This pigment most closely resembles the discontinued and toxic Verdigris.

Permanence

Phthalo Greens are completely lightfast and resistant to alkali, acids, solvents, heat, and ultraviolet radiation. They are currently used in inks, coatings, and many plastics due to their stability and are considered a standard pigment in printing ink and the packaging industry.

Toxicity

Phthalo Green has no significant hazards, but it contained PCBs (polychlorinated biphenyls) until 1982.

History

This bright blue-green was developed in 1935 and has been in use since 1938.