Rublev Colours Dry Pigments - Series 2 Slate Grey is a naturally occurring mineral pigment prized for its quiet, stony neutrality and gentle mixing behaviour. Also known as Slate Black (PBk 19 / C.I. 77017), this low-tinting strength grey is ideal for atmospheric passages, architectural tones, and underpainting where you want subtle value control without overpowering colour.

Slate Grey is made by finely grinding natural slate, a metamorphosed mudstone/shale composed of extremely fine crystalline minerals. This pigment consists primarily of mica (muscovite/illite type) with chlorite (clinochlore type) and quartz, plus minor iron-bearing phases that contribute to its natural grey tone. The result is a restrained, stone-like grey that reduces chroma gently, cooling and greying colours without the harshness or dominance of a strong black. In paint films it often produces a natural, matte surface character that suits tonal work and understated palettes.

Sourced from slate deposits in the Ardennes region of France, Slate Grey offers a stable, inorganic mineral composition, making it well suited to mixing with other artists’ pigments in oil, acrylic, watercolour, and other common binders. It mulls readily into oil and disperses well in water-based mediums, making it a practical choice for artists who hand-make paints or want a mineral extender-style grey with character.

Key features

• Natural mineral grey with low tinting strength

• Softly greys and cools mixtures without harsh blackening

• Excellent for underpainting, architectural tones, and atmosphere

• Disperses well and mulls easily

• Often yields a natural matte surface character

Key specs

• Colour Index: PBk 19 (C.I. 77017)

• Pigment type: Natural inorganic

• Composition: slate mineral mix (mica + chlorite + quartz)

• Oil absorption: 43 g oil / 100 g pigment

• Density: about 2.7 to 2.9 g/cm3 (typical)

• Size: 100g

Handling and safety
Low toxicity in normal use, but as with all powdered minerals avoid inhaling dust and avoid unnecessary skin contact. Use good ventilation and a properly fitted dust mask or respirator when handling dry pigment or sanding dried films. Conforms to ASTM D4236.