Divine Proportion

The only collection of drawings Leonardo managed to publish in his lifetime were the illustrations for Luca Pacioli's book, De divina proportione (On divine proportions). Luca Pacioli was a Franciscan friar and Leonardo picked up a lot of mathematical knowledge from him in the period 1496-1501 when both of them worked for the Duke of Milan, Ludovico Sforza. Leonardo made for Pacioli's book, whose theme were proportions in geometry and architecture, about sixty illustrations that showed polyhedra. The illustrations were printed using the woodcut techique and that could be the reason that Leonardo in his Notebooks wrote down that all that should be published from his work should be made in the copperplate technique, and not woodcuts.