Alizarin was the first natural dye to be synthesised artificially, achieved by German chemists Graebe and Liebermann in 1868. Before synthesis, it came from the madder root — cultivated since ancient Egypt and Rome for red dyeing.

Alizarin crimson is the red of deep emotion — cooler and more melancholy than scarlet, with a blue undertone that makes it ideal for shadows. It reads as passionate but controlled, the red of wine rather than blood.

Rubens, Rembrandt, and Delacroix all used madder-based alizarin for flesh shadows and drapery. The Impressionists favoured it for its transparency in glazing. Turner used it extensively, which is why many of his paintings have faded dramatically — early alizarin was fugitive.