From the exhibition in the Fitzwilliam Museum
In 1828 French chemist Jean-Baptiste Guimet discovered a means of preparing synthetic lazurite by heating together china clay, soda, charcoal, quartz and sulphur. The new pigment became known as French ultramarine. It was a fraction of the cost of the original.
By the 1870s French ultramarine was the standard, despite artists complaining that it lacked the depth of blue derived from lapis lazuli.
Synthetic ultramarine was later used as an ingredient in laundry soap, to enhance the optical properties of white. A tiny amount of blue offsets the yellowing that occurs from repeated washing and makes white fabric look brighter.
Laundry blue, marketed as Reckitt’s Blue in England, was taken to the colonies where European notions of ‘cleanliness’ and domestic service were imposed on local populations. The soap powder was subverted and transformed.
The highly desired ultramarine colour produced by Reckitt’s Blue was used by Indigenous artists across Africa, the Americas and the Pacific to decorate a wide variety of special items.
My mother used a form of Reckitt’s Blue marketed as Dolly Blue in a small muslin bag that she would put with the wash in the washing machine.