Abstract: A high resolution thermal printer capable of printing both directly on a thermally responsive media and indirectly through a thermally responsive donor media is disclosed. The printer has a printing media guide mounted as an intermediate clamshell structure to accurately position the printing media immediately adjacent the print head and platen. The printing media guide includes a nip roller and guide bar independently suspended on a spring biased, pivot plate arrangement. The printing media is centered on the supply spool, and the printer includes a read/write circuit to communicate with a profiler chip centrally mounted in the printing media roll. The printer may also include a read/write circuit to communicate with a donor profiler chip centrally mounted in the donor media roll. A constant pressure brake with a friction belt is used directly against the printing media. A spring arm latch/channel block arrangement is used to secure the printing media supply spool.