Michael Harding Artists Oil Colours - Ultramarine Blue (No. 113) - 40ml

Inorganic – No. 113 is an obviously beautiful mid-blue. The discovery in the 1820s of a Sodium Sulphosilicate compound, which had appeared as a mysterious blue deposit on soda-ash furnaces, was a liberating moment for financially challenged artists everywhere. Up to then the only available version of this compound was the often-unobtainable Lapis Lazuli ore, mined in Afghanistan. Ultramarine has a high tint power, and Michael Harding's chosen shade produces strong green shade blue hues and makes wonderful violets with Magenta and the red Lake colours. It is also useful in greens and greys. The only chemical weakness is a recorded sensitivity to atmospherically borne acids, which can bleach it out. Ultramarine Blue is one of the more difficult paints to make, as it forms an intractable runny syrup when first ground into oil, which must then be stabilized with a small amount of wax.

Colour Index PB29
Drying Speed Average
Transparency Transparent
Lightfastness Excellent
Oil Content Average
Tint Power Average
Toxicity Non-Toxic
ASTM D-4236 Yes