1. A method of printing on a medium comprising the steps of: detecting a type of medium; entering a printing mode as a function of the type of medium detected in the detecting step, the printing mode being either an envelope printing mode or a tape printing mode, when in the envelope printing mode: positioning a print module at a first position; printing postal indicia data on a first area of the envelope; positioning the print module at a second position; obtaining additional data; printing the additional data on a second area of the envelope; positioning the print module at the first position; obtaining recipient address data; and printing the recipient address data on a third area of the envelope; positioning the print module at a third position; obtaining sender address information; and printing the sender address information on a fourth area of the envelope.