Cornelissen's has been in business since 1855 and you can't beat the shop for character, with its shelves stacked with bottles of pigments and little packets of all sorts of traditional artist's materials (plus the more 'usual' supplies). Don't be intimidated by it looking like a shop for serious professional artist's only, the staff friendly and helpful, and they don't mind if you just gawk at things such as "dragon's blood" (a natural resin).