A couple of years ago, I did a copy of a portion of Sandro Botticelli's La Primavera. It is in tempera grassa on panel, 16 x 20".
You can see the original Botticelli painting here.
Tempera grassa is an emulsion composed of egg yolk and a drying oil (linseed in this case) mixed with pigment. It was commonly used in Italy during the transition from egg tempera* to oil painting in the 15th century; Botticelli used it to paint the original.
You can see a writeup of how I made this painting here.
Tempera grassa continued to be used through the Baroque period, but mostly fell out of use after that. During the 20th century, as a variety of traditional media such as fresco and egg tempera were revived, it came back into limited use, most notably by Pietro Annigoni.
*If you don't know what egg tempera is, then you're not an art geek like me. Just keep reading this blog. We'll have you up to speed in no time.