stiffness to function in commercial register printers accordingly the present film which preferably has a thickness of from about 0 50 mils to about 0 75 mils must have a 1 secant modulus in the machine direction of at least about 150 000 psi preferably at least about 200 000 psi in order to achieve this stiffness preferably the film is uniaxially oriented in the machine direction with a machine direction stretch ratio in the range of from about 1 5 u00d7 to about 10 0 u00d7 this degree of orientation improves machine direction stiffness by 2 to 5 times as compared to a non oriented film alternatively the film may be biaxially oriented such that the product of the machine direction and transverse direction stretch ratios is from about 2 0 u00d7 to about 50 u00d7 in accordance with the present invention orientation may take place in one step or in a series of stretching steps regardless of the type of orientation thereafter the film must be thermally stabilized i e annealed or heat set in order to render it essentially non heat shrinkable orientation and annealing may be performed either in line out of line with coextrusion following orientation and heat stabilization the outer film surface 19 preferably is subjected to a surface treatment such as preferably corona discharge flame or chemical treatment prior to application of the thermal image coating if an anti static coating is employed the surface onto which it is applied preferably is subjected to a surface treatment prior to coating as well such surface treatment is employed to ensure adherence of the coating to the.