QoR Modern Watercolors - Permanent Gamboge, 11 ml tube

Pigment Information

This color contains the following pigments:

PY42-Yellow Iron Oxide

PV19-Quinacridone Violet

PY150-Nickel Azo Yellow

Pigment Name

PY42-Yellow Iron Oxide

Chemical Name

iron(III)-oxide, hydrated

Chemical Formula

Fe2O3 • H2O

Properties

Yellow Ochre provides artists with earthtones from cream to brown. It has good hiding power, produces a quick drying paint, and can be safely mixed with other pigments. Its transparency varies widely from opaque shades to more transparent ones, which are valued for their use as glazes. If gypsum is present, Yellow Ochre is not suitable for frescoing. (See Brown Ochre, PY43.) PY42 is made from synthetic iron oxides. PY43 is made from natural iron oxide.

Permanence

Yellow Ochre has excellent permanence because ochres are some of the most permanent pigments available.

Toxicity

Yellow Ochre is non-toxic unless it contains manganese.

History

Ochre comes from the Greek word ochros, meaning pale yellow. It was one of the first pigments to be used by human beings, and evidence of its use has been found at 300,000 year old sites in France and the former Czechoslovakia.

Pigment Name

PV19-Quinacridone Violet

Pigment Type

organic synthetic, quinacridone

Chemical Formula

C20H12N2O2

Properties

Quinacridone Red is a high performance, transparent pigment with an average drying time and uneven dispersal. It is another name for Quinacridone Violet (PV19) and Quinacridone Red (PR192). Quinacridone pigments have relatively low tinting strength in general. For this reason, quinacridone colors are often expensive, because more pigment is required in the formulation.

Permanence

Quinacridone Violet has excellent lightfastness and is considered the most lightfast organic pigment in this shade range.

Toxicity

Quinacridone Violet has no known acute hazards. Overexposure to quinacridone pigments may cause skin irritation. Quinicridone pigments contain a compound found to be a skin, eye, and respiratory irritant.

History

Although quinacridone compounds became known in the late 19th century, methods of manufacturing so as to make them practical for use as commercial pigments did not begin until the 1950s. Quinacridone pigments were first developed as coatings for the automotive industry, but were quickly adopted by artists.

Pigment Name

PY150-Nickel Azo Yellow

Pigment Type

inorganic

Chemical Name

nickel azomethine yellow

Chemical Formula

C30H18Cl2N6NiO4

Properties

Nickel Azo Yellow is a transparent, moderately staining yellow pigment with high tinting strength. It is considered a good color match in botanical and landscape painting for natural gamboge (NY24), a historic yellow pigment with fair to poor lightfastness.

Permanence

Nickel azomethine yellow has excellent lightfastness.

Toxicity

Nickel azo yellow pigment is mildly toxic, and is often labeled as hazardous. Avoid respiratory and skin exposure to pigment dust. It should be disposed of properly with other hazardous wastes, not washed down the sink.

History

Nickel azomethine yellow has been developed as an artist pigment becasue it is a close match for gamboge, a historic yellow.