I recently visited L.Cornelissen & Son, Artists’ Colourmen in London. I was in heaven – or maybe ferret shock – WALLS of colorful pigments. They’ve been in business for over 150 years & carry every sort pigment possible. I restrained myself to taking pictures and buying just 4 tubes of Schminke watercolors. But, I also got the catalogue which shows all their products and has “recipes” for making oils, watercolors, pastels, acrylics and more!