Like many left-handed people of Leonardo’s era, he habitually wrote backwards.
A by-product of being excluded from a normal education because he was an illegitimate child is that no one discouraged Leonardo from preferring his south paw. Contrary to the widespread belief that the practice was a way for lefties (considered devient, suspect or even satanic) to hide their work, it was a way to avoid dragging their hands through the ink. The same applied to his drawing, and centuries later his hatching strokes– made in the same direction as today’s back slashes–helped experts authenticate artworks as those of Leonardo. A recent example occurred in 2016, when the fact that a pen-and-ink study of St. Sebastian tied to a tree was drawn by a left-hander helped clinch the case that it was a Leonardo. “My eyes jumped out of their sockets,” Carmen Bambach, a curator at New York’s Metropolitan Museum of Art told the New York Times. “The attribution is quite incontestable.” The Tajan auction house will put the work, which is barely bigger than a postcard and has two scientific drawings on the back, under the hammer on June 19, estimating its value at between 15 and 20 million euros.
Reading mirror writing is a simple matter of holding it against a mirror. Try it with these notes on da Vinci’s Vitruvian Man drawing!