PET Roll Calculator PicturePlease use the Polyester (PET) Roll CalculatorĀ to discover the roll weight for film you may purchase. Please note that there could be a slight variation in the actual weight of the final product depending on the film type as there may be slight variations in the density of film types. This tool should be used as a general guide. For questions, or additional information please Contact Us. Please click here to search for detailed technical information.