In 1692 a Dutch painter named A. Boogert made one copy of a 900-page manual on mixing watercolours, with more than 700 pages of hand-painted swatches: five squares to a page, numbered, each shade stepped up or down by adding “one, two or three portions of water.” It looks like a Pantone fan deck made 270 years early. The Bibliothèque Méjanes in Aix-en-Provence has put every page online as a zoomable scan.