Caran d’Ache have created the Caelograph Collection, which includes several writing instruments that map the movement of the stars. This collection, which is available in limited editions of rose gold or platinum, includes a fountain pen, roller pens, an inkwell, and a compass. The constellations and a map are engraved on the body of the pen, and by calibrating the pen, users can learn the position of the stars at any time of year as well as the zenith, compass points, and the horizon line.