Young Girl Holding a Bird. In 1757 a printmaker named Jean-Charles Fran?ois developed a printing technique to make facsimiles of chalk drawings. He perfected his method by inventing tools with toothed points of varying thicknesses set at irregular intervals and angles, imitating the random character of grains of chalk on textured paper. Demarteau adopted Fran?ois's specialized implements to copy the chalk drawings of such well-known artists as Le Prince and Fran?ois Boucher.