Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
This color contains the following pigments:
PB27—Antwerp Blue
Pigment Type
inorganic
Chemical Name
ferric ammonium ferrocyanide
Chemical Formula
C18Fe7N18
Properties
Antwerp Blue is a slightly warm and less saturated blue with good transparency and undertone clarity. It is a pale variety of Prussian Blue with 75% inert pigment. It has similar properties to pure Prussian Blue, but its overall performance is inferior.
Permanence
Antwerp Blue can fluctuate, fading in the light and recovering in the dark. In watercolor form, it fades when mixed with white pigment or extender. Although it has reasonably good lightfastness and permanence, it is not considered ideal for permanent painting.
Toxicity
Antwerp Blue is mildly toxic by ingestion, but is considered safe for external use. In the United States, ferric ferrocyanide is permitted as a coloring ingredient for externally applied cosmetics, but not for lipsticks or internal use. If the pigment is exposed to ultraviolet radiation, heated, or treated with acid, it becomes reactive and releases toxic hydrogen gas.
There has been some confusion and controversy about whether ferric ferrocyanide and ferric ammonium ferrocyanide should be classified as a "cyanide" and as a toxic or environmental pollutant. The United States Environmental Protection Agency has issued an administrative ruling that ferric ferrocyanide is not a toxic pollutant, and that its use as an ingredient in road salt and deicing mixes is permitted.
History
Antwerp Blue was developed through experimentation with Prussian Blue.
Alternate Names
Haarlem Blue, Mansa Blue, Mineral Blue
PV23—Dioxazine Violet
Pigment Type
organic
Chemical Name
carbazole dioxazine
Chemical Formula
C34H22Cl2N4O2
Properties
Dioxazine Violet is transparent and has very high tinting strength. It is a staining pigment, very dark valued when it is used at full strength. Concentrated, it paints out nearly black, but it mixes with Titanium White to form bright, opaque tints of purple. PV23 produces slightly redder shades than PV37. Because the hue can vary with the conditions of preparation and grinding, it may be offered in red shade, blue shade, and so forth.
Permanence
Dioxazine Violet has good lightfastness. There may be some concern about it fading or shifting in color in tints and washes. Some artists have reported that PV37, a molecular variant, is more lightfast than PV23.
Toxicity
n/a
History
Two molecular variants of Dioxazine Violet, PV23 and PV37, are available. They have similar properties, but mix slightly differently.
Alternate Names
Dioxazine Purple, Chromothal Violet, Mauve, Carbazole Violet.
PBk7—Lamp Black
Pigment Type
inorganic
Chemical Name
carbon
Chemical Formula
C
Properties
Lamp black is a very opaque, heavily staining black pigment that does not have much covering or tinting power. It is typically the most opaque black in watercolor form. Though a very pure black, it tends to muddy slightly in mixtures. Natural sources may be brownish or bluish in tone because of impurities. When used in oil paints, it is one of the slowest drying pigments, and should not be used in underpainting or applied in layers underneath other colors.
Permanence
Lamp Black is very lightfast and absolutely permanent. It is used in all techniques in permanent painting.
Toxicity
Carbon itself is not considered hazardous, however other combustion products that are hazardous are often present as impurities when Lamp Black is produced from natural materials. For this reason, commercial preparations of the pigment should be considered slightly toxic. Avoid skin contact and inhalation. Where such impurities are present, Lamp Black is a possible human carcinogen.
History
Lamp Black is a carbon based black traditionally produced by collecting soot (known as lampblack) from oil lamps. It has been used as a pigment since prehistoric times. It is the black found in Egyptian murals and tomb decorations and was the most popular black for fresco painting until the development of Mars Black.
Alternate Names
Carbon Black, Channel Black, Furnace Black, Oil Black, Vegetable Black. Flame Black is an impure version of Lamp Black. An alternate spelling is Lampblack, in which the first syllable is stressed and the two words are elided to form a closed compound.
