Indathrone Blue

Description

Indanthrone Blue (PB60) is a handmade single-pigment anthraquinone blue, sometimes known as Indanthrene Blue or Anthraquinone Blue. It produces a deep, inky navy blue with a slightly violet-leaning undertone and a richly saturated masstone. Compared to ultramarine or phthalo blue, this pigment is darker and more velvety, with less green bias than phthalo and more depth and “inkiness” than most cobalts or ultramarines.

In use, Indanthrone Blue gives a powerful, controlled blue ideal for night skies, deep water, stormy weather, architectural shadows, and expressive low-key passages in both landscape and figurative work. It has very strong tinting strength and a staining, transparent to semi-transparent character, making it exceptional for glazing, layered washes, and building luminous, dark passages without chalkiness. It mixes beautifully with warm earths and oranges for near-blacks and deep neutrals, with reds and violets for complex wine blues and blue-violets, and with phthalo or cobalt blues to extend the range from luminous mid-blues to deep, atmospheric indigos.

This anthraquinone pigment is highly lightfast, chemically stable, and compatible with a wide range of binders and mediums. In artist’s colors it offers a modern, high-performance alternative to traditional indigo and Prussian blue, functioning as a workhorse deep blue for serious glazing, rich shadows, and palettes that need both intensity and subtle control in the dark values.

History

Indanthrone Blue belongs to the anthraquinone family of vat dyes and pigments developed in the early 20th century, originally for the textile and industrial color industries. These colors were designed for exceptional fastness to light, washing, and chemicals, and Indanthrone Blue quickly gained a reputation as one of the most durable synthetic blues available.

As pigment technology advanced, the dye chemistry behind Indanthrone Blue was adapted into a finely divided, insoluble pigment suitable for paints, inks, and coatings. Its combination of depth, permanence, and beautiful handling led to its adoption in artist materials under names such as Indanthrone Blue, Indanthrene Blue, and Anthraquinone Blue. Today PB60 is widely regarded as one of the most useful deep blues on the modern palette, prized by painters who want a reliable, lightfast, and expressive alternative to traditional dark blues and historical indigo.

Pigment Information

Pigment Type: Synthetic (Organic) anthraquinone pigment

Suitable Mediums: Watercolor, Oil, Tempera, Acrylic, Lime / Fresco, Ceramic and cement applications

Lightfastness: Best

Opacity: Transparent to semi-transparent (very strong tinting and staining)

Other Names: Indanthrone Blue, Indanthrene Blue, Anthraquinone Blue (PB60)

Color Index Code: PB60