Having a reflective surface on your growing chamber walls can greatly maximize the amount of light available to your plants. Mylar reflective film has the ability to reflect back almost 92% of the light that hits it. Developed by NASA, Mylar is strong, durable, and does not tear easily. Mylar film has a standard width of 50 inches. Depending on your requirements, Mylar film is available in rolls of 25, 50, and 100 feet length.