R&F Encaustic Paint Block - Prussian Blue, 40 ml
It is powerful and velvety, the deepest, reddest of all blues. It has a slightly grainy texture. It may not be lightfast in tints.
- Pigment Composition: PB27-Prussian Blue
- 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, it can behave erratically and less reliably in oil and watercolour form. 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 of 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. The potash Diesbach purchased from a local laboratory had been contaminated by animal oil and blood during previous experimentation. The resulting mixture yielded a very pale red that changed to purple and then 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.
