The greenhouse allows you to start growing early in the spring and extend the gardening season in the fall. Greenhouses can be built from scratch or ready-made greenhouses can be purchased, but any green greenhouse can be. . . The greenhouse allows you to start growing early in the spring and extend the gardening season in the fall. Greenhouses can be built from scratch or ready-made, but any greenhouse requires greenhouse film to cover it and make it work. Before you decide which one is best for your needs, it is important to know something about greenhouse coverings. The greenhouse film also has several names, including agricultural plastic or poly film, made of polyethylene plastic. The greenhouse film is different from polyethylene film for other purposes, such as paint or waterproof cloth covering furniture. The greenhouse film is UV resistant and does not break down quickly when exposed to sunlight, and can last for multiple seasons if applied correctly. There are many ancillary products that can also be used to connect greenhouse film to the structure it covers. There are prefabricated Batten strips, latches for bundling paper, and special clips for connecting film to PVS pipes of different sizes. Anti-UV repair tape rolls for fixing tear and sealing overlap are also sold. The width and thickness of the greenhouse film are different. The most common thickness is 4 mil and 6 mil. The size of the greenhouse, the weather conditions in your area, and your budget will determine which thickness is best for you. This film is also clear or white, and some kinds of film have opaque places to ensure a certain degree of shadow in the greenhouse. Some gardeners use double-layer greenhouse film to achieve insulation. There are four brands. year warrantee. Greenhouse film is sold for square feet and is available in many garden and agricultural supply stores.