Abstract Technical and analytical studies were carried out on a late Graeco/early Roman Egyptian cartonnage from the University of Southern California (USC 9428). The structure of the object was visually examined, and the layers of textile and plaster were identified as linen, wood fibres of mixed origin, and a lime-based plaster. Using a combination of techniques, the pigments used to decorate the cartonnage were identified as minium, Egyptian blue, green earth, a copper proteinate green, a mixture of Egyptian blue and iron ochres, a mixture of green earth and Egyptian blue, orpiment, hydrocerussite, a lac dye and a carbon lamp-black. The discovery of previously unrecognized and apparently rare pigments, such as a copper proteinate pigment from 350 BC, suggests that there is still much work to be done on the use of pigments and the techniques of painting and cartonnage production.