Rublev Colours Dry Pigments - Mars Crimson is a premium synthetic micronised red iron oxide pigment chosen for its deep, bluish-red undertone and exceptional permanence. As the bluest shade in the Rublev Mars red collection, Mars Crimson (PR 101) is ideal when you want an iron oxide red that leans cooler, producing rich wine reds, muted violets, and elegant shadow reds without the orange warmth typical of many earth reds.

Made from highly stable ferric oxide (Fe2O3), Mars Crimson is one of the most permanent colours available to artists. It delivers dependable performance across oil, acrylic, and water-based paint systems, with ASTM Lightfastness I in acrylic, oil, and watercolour. Because it is micronised and spherical in particle shape, it disperses smoothly and forms an even, coherent paint film, making it an excellent choice for hand-mulling and professional paint making.

Mars Crimson has a relatively low to moderate oil demand (15 to 25 g oil per 100 g pigment), allowing you to grind a stiff paste without excessive binder. It is well suited to underpainting, tonal work, portrait shadows, muted reds, and colour mixing where you want permanence and subtle cool control.

Key specs

• Colour Index: PR 101 (77491)

• Pigment type: Synthetic inorganic (micronised red iron oxide)

• Chemical formula: Fe2O3

• ASTM lightfastness: I (Acrylic, Oil, Watercolour)

• Particle shape: spherical

• Density / specific gravity: 5.50 g/cm3

• Oil absorption: 15 to 25 g oil / 100 g pigment

• Heat stability: up to 750 C

• Iron content (Fe2O3) minimum: 96%

• Size: 100g

Handling and safety
Not considered hazardous in typical use, but as with all dry pigments avoid inhaling dust and avoid ingestion or prolonged skin contact. Conforms to ASTM D-4236. FDA approved for regulated polymer food contact applications (21 CFR 178.3297).