 The sitter climbed into a wooden frame (1.75m high x 6.5m wide), sat and turned to the side to pose.A pantograph connected to a pencil produced within a few minutes a "grand trait", a contour line on a piece of paper.With the help of a second scaling down pantograph, the basic features of the portrait were transferred from this sheet in the form of dotted lines to a copper plate which had previously been prepared with a ground for etching.