Choose thickness according to the finished item and the machine’s supported range. Thinner film works well for documents that need flexibility, economical protection, or easy filing. Thicker film provides more stiffness and may suit frequently handled signs, instructions, reference sheets, or presentation materials. The total finished thickness includes both film layers and the document, so very heavy stock may require a lower film thickness. Confirm that the cartridge and machine are designed for the chosen material. Using unsupported thickness can cause poor feeding, incomplete bonding, curling, or jams. A sample run is useful when changing document stock or film thickness.