R&F Pigment Stick - Prussian Blue, 38 ml
The deepest, reddest of all blues, it is robust and incredibly velvety. It has a slightly grainy texture and may not be lightfast in tints.
- Pigment Composition: PB27-Prussian Blue
- Dimension: 38 ml. stick measuring 5" x 3/4" diameter
- Paint Lines: Encaustic, Pigment Stick
- Opacity: Transparent
- Pigment Stick Drying Rate: Fast
- Classification: Synthetic Inorganic
- Chemical Composition: Quinacridone violet, cadmium red, zinc-titanium white
- Safety Information: Conforms to ASTM D-4236
Pigment Name: PB27 Prussian Blue
Classification: Synthetic Inorganic
Chemical Composition: Ferric ferrocyanide/iron (III)-hexacyanoferrate (II)
Properties
Prussian Blue is a semi-transparent, deep cyan-blue with a greenish undertone and a very high tinting strength unequalled by most pigments. It is similar to Phthalo Blue unless mixed with white when it gives up intensity and becomes smoky. Depending on its manufacture in oil and watercolour form, it can behave erratically and less reliably. For permanent painting, Phthalo Blue is considered a more reliable choice.
Permanence
Prussian Blue is lightfast and permanent in all techniques except for fresco. When mixed with Zinc White in watercolour or tempera form, it fades upon exposure to light and completely regains its chromatic strength in the dark. Modern manufacturing techniques have made this tendency less an issue in recent years.
Toxicity
Prussian Blue is moderately toxic if ingested. It will emit toxic hydrogen cyanide gas if heated, exposed to ultraviolet radiation, or treated with acid.
History
The first of the modern pigments, Prussian Blue, is the first artificial pigment with a known history. It was discovered by accident in 1704 by the Berlin colour maker Heinrich Diesbach, who tried to create a pigment with a red hue by mixing iron sulphate and potash. During previous experimentation, the potash Diesbach purchased from a local laboratory had been contaminated by animal oil and blood. The resulting mixture yielded a very pale red that changed to purple and deep blue when he tried to concentrate it. Since previous blue pigments came from lapis lazuli, an expensive stone, Diesbach's discovery was significant for artists of the time.
