100 u03bcm and preferably 30 50 u03bcm we target then particulates of characteristic dimensions of 50 u03bcm u00d7 50 u03bcm u00d7 1000 u00e5 i e 1 u03bcm we have discovered that films of the desired thickness can be prepared by sputtering the metal onto 2 mil thick fluorinated ethylene propylene fep sheetstock making this film product is done according to the conventional processing steps for making food or vacuum bagging materials the method of the present invention removes the metal from the metallized film in two simple and quick immersion steps first the metallized roll is immersed in a caustic basic bath for about 15 sec to loosen the metal then we immerse the roll again for about 15 sec in a dilute acid solution to neutralize the base and to separate the metal we brush the particulates from the fep and precipitate the particulates in the acid solution prior to filtering rinsing and drying to separate the metal from the fep i generally contact the metal with one or more counter rotating cylindrical nylon bristle brushes i sometimes use ultrasonic vibration alone or in combination with the brushing for aluminum thin films i prefer to use 7 by wt na 2 co 3 as the base but can use nahco 3 naco 3 nahco 3 mixtures or conventional alkaline or alkaline earth hydroxides diluted to about a ph of 9 0 the acid solution preferably is 0 01 0 1n acetic acid at ph 3 4.