Benzimidazo Blue Pigment

Description

Benzimidazolone Blue (PB80) is a high-chroma, transparent to semi-transparent organic blue with a distinctly reddish-blue / blue-violet hue. It belongs to the benzimidazolone-dioxazine family of high-performance pigments. In paint it brings very strong tinting strength, smooth films, and clean mixes that lean toward vivid violets rather than greenish blues. Compared to Phthalo Blue (PB15), PB80 is less green and more violet; compared to Indanthrone (PB60), it's higher-chroma and lighter in masstone, making luminous violets and periwinkles in tints. In watercolor it is highly staining and excels in layered glazes; in oils and acrylics it yields saturated, modern violets and deep navy blues.

History

Commercialized in the late 20th century as a durable, metal-free alternative for demanding coatings, PB80 appears under trade names such as Hostaperm Blue R5R and similar benzimidazolone-dioxazine blues. It was used in automotive and industrial finishes for its excellent light and weathering fastness, and is a discontiuned, extinct pigment.

Pigment Information

Pigment Type: Synthetic organic (benzimidazolone-dioxazine)

Suitable Mediums: Watercolor, Oil, Tempera, Acrylic, Encaustic, Cold Wax, Casein, Milk, Swedish Flour

Lightfastness: Excellent

Opacity: Transparent

Other Names: Benzimidazolone Blue; Hostaperm Blue R5R

Color Index Code: PB80

Image: 'A Wheatfield with Cypresses' by Van Gogh from the National Gallery