Those 7000 statues in the Terracotta army were apparently lacquered and then painted and then covered in egg. Or it might have been egg paint. Depends on which sentence I understood correctly.
The most interesting part for me were the colors and how they got them:
The researchers thought animal glue might have served as a binder, but all of the data pointed to egg instead. The pigments, they found, were bone white, lead white, cerussite (which sparkles), quartz, cinnabar, malachite, charcoal black, copper salts, Chinese purple and azurite.