finished product consisting of the substrate having the paint coated film bonded thereto had an excellent smooth surface appearance including good gloss and distinctness of image in unstretched as well as stretched areas a second sheet material made as described in example 1 was flawed due to the presence in some areas of coating streaks and of a wavy pattern which were introduced presumably during the coating of the paint layer a first sample of a flawed area of the sheet material referred to hereinafter as 34 the second composite 34 was bonded to a substrate by the conventional precedure described in example 1 the finished product had a non uniform surface appearance because the coating flaws had been retained throughout the thermoforming operation furthermore while the initially present defects had remained essentially unchanged in unstretched areas their shape and configuration had been accentuated in proportion to the degree of stretching of the film defects in the form of markings running lateral to the direction of stretch were noticeably widened a second sample of the flawed section of the sheet material of example 2 was bonded to a substrate by the procedure according to this invention which differed from the conventional procedure described in examples 1 and 2 by preheating and cooling the film prior to the application of the thermoforming heat 2 preheated to a temperature of about 150 u00b0 c at which it becomes taut within the frame 3 allowed to cool for 1 5 minutes to about 38 u00b0 c without losing its tautness in this stage the clamped.