|"Yellow Reflections (on the road to Evora)"/pastel/9x7|
Robert Genn's "The Story of Yellow" discusses the five main sources of yellow pigment. I recalled learning about one of those--cow urine (ever heard of Indian Yellow? Yep!)--while touring India a few years ago. Genn publishes an informative Twice-Weekly Letter and his website, The Painter's Keys, is a goldmine of info for artists.