1. A processing system for digitizing a freehand graphic created by an optically imaging pen, the processing system being configured for: receiving digital ink representing interaction of the pen with a surface having a position-coding pattern printed thereon, said digital ink identifying one or more positions detected by the pen; determining if the detected position is in a first area or a second area of the surface; if the detected position is in the first area of the surface, then interpreting the position as a point in a freehand graphic; and if the detected position is in the second area of the surface, then interpreting the position as a selection of a property for the freehand graphic.