Polyamide resins, with very high melting points, excellent clarity and stiffness. Two types are used for films: nylon-6 and nylon-66. The latter has much higher melt temperature, thus better temperature resistance, but the former is easier to process, and it is cheaper. Both have good oxygen and aroma barrier properties, but they are poor barriers to water vapor. Also, nylon films can be cast (see CAN), or oriented, (see BON).