A system for determining the orientation of digital ink is provided having a sensing pen and a processor. The system measures the orientation of the pen during writing by the pen on a surface printed with tags. Each tag encodes data on an identity of the surface associated with a digital description of the surface and on the respective location of that tag on the surface. The digital ink is generated by associating the digital description with the data encoded by the tags sensed by the pen during said writing. The orientation of the digital ink is determined using the measured orientation of the pen.