methods and apparatus are provided for permanently and rapidly imparting surface characteristics , such as texture or graining , to decorative coverings for substrates , such as wall coverings in the absence of any degradation thereof , so that when the coverings are subsequently applied to the substrate , such as an aircraft bulkhead , by heat application , the texture previously imparted will remain intact . the process and apparatus uses magnetic attraction in tenter frames to carry and expose continuous webs of thermoplastic to high temperature embossing with simultaneous and subsequent rapid cooling . the arrangements and process avoid lengthy press application at high temperature which has the effect of degrading color and other characteristics of the material being treated .