Those little Kapton based flexible heaters I got for the makerbot platform - I've done some testing with them. The optimum voltage is 20-24vdc. The thermostat thats built-on to the circuit board (Airpax 66L065- http://www.datasheetdir.com/66L065+download
) limits the temp to +65C. Very hot to be sure but not 100C that the makerbot guys run there platform at. Airpax has a 66L095 part that would limit the temp to 95C. Not sure if this little board could handle it though.