Recommended reading

The Materials and Techniques of Medieval Painting, by Daniel V. Thompson. This small book is great, even if you're not an art geek like me. Thompson was one of those rare authors who was both completely immersed in his small area of specialization and also able to explain it in chatty, comfortable, engrossing detail to people who don't know anything about it. It's a little dated (for example, he was writing before the rediscovery of lead tin yellow as the standard artificial opaque yellow pigment from the later Middle Ages through the Baroque period), but for the most part it's a great survey of how artists painted back in the day.