non graphite pencils were used already Leonardo Da Vinci 500 years ago [0] on all his sketches. Them were made by a Silver alloy. In modern times the idea was r

non graphite pencils were used already Leonardo Da Vinci 500 years ago [0] on all his sketches. Them were made by a Silver alloy. In modern times the idea was rediscovered and modernized and patented by Pininfarina [1]. [0] https://en.wikipedia.org/wiki/Silverpoint https://en.wikipedia.org/wiki/Silverpoint [1] https://www.pininfarinasegno.it/en/crafted-innovations/ethergraf/ https://www.pininfarinasegno.it/en/crafted-innovations/ether...