Ultramarine - Synthetic Alternatives

Synthetic Alternatives

Synthetic ultramarine is a more vivid blue than natural ultramarine, since the particles in synthetic ultramarine are smaller and more uniform than natural ultramarine and therefore diffuse light more evenly.

Artificial, like natural, ultramarine has a magnificent blue color, which is not affected by light nor by contact with oil or lime as used in painting. Hydrochloric acid immediately bleaches it with liberation of hydrogen sulfide. Even a small addition of zinc-white (oxide of zinc) to the reddish varieties especially causes a considerable diminution in the intensity of the color, while dilution with artificial precipitated sulfate of lime ("annalin") or sulfate of baryta ("blanc fix") acts pretty much as one would expect. Synthetic ultramarine being very cheap, it is largely used for wall painting, the printing of paperhangings and calico, etc., and also as a corrective for the yellowish tinge often present in things meant to be white, such as linen, paper, etc. Bluing or "Laundry blue" is a solution of synthetic ultramarine (sometimes, prussian blue) that is used for this purpose when washing white clothes. Also often found in make up such as mascaras or eye shadows. Large quantities are used in the manufacture of paper, and especially for producing a kind of pale blue writing paper which is popular in Britain. During World War I the RAF painted the outer roundels with a color which was made on Ultramarine Blue. This became BS 108(381C) Aircraft Blue. It was replaced in the 1960s by a new color made on Phthalocyanine Blue, BS110(381C) Roundel Blue.