Cord from deknudt mirrors

The Cord mirror is a design from Roberto Paoli, who took inspiration from the geometric work of Kepler. The circular mirror is divided with a cord (in geometry, the segment connecting two points of a circle without passing through its center can be defined as cord). Roberto Paoli followed the proportions chosen by Kepler and emphasized the difference between the two parts of the circle, distinguishing them with mirrors of different colours.