Portrait miniatures – usually painted using watercolours of enamel. Popular until photographic portraits became available. Developed from techniques used in the paintings of illuminated manuscripts. As well as ivory, miniatures were commonly painted onto chicken skin, cardboard and playing cards. There are also illuminated manuscripts, Persian and Ottoman miniatures, and figure painting.
Hilliard used gold to bring light into the painting.
Goya created these miniatures by coating the ivory with a layer of black carbon then wiping away the colour using water to reveal the white underneath.