Unusual stories of the bizarre and gruesome things that have been used as paint pigments from Kassia St Clair, author of The Secret Lives of Colour. Plus, why did Van Gogh create portraits of the man who sold him his paints? Nienke Bakker, Curator of Paintings at the Van Gogh Museum in Amsterdam, brings us the story of Père Tanguy whose arts supply shop was at the heart of the Paris art scene. Produced and presented by Viv Jones.