6.4 Other Cushioning Systems
Two major alternatives to the use of plastic foams as cushioning materials also rely on the use of air to provide resiliency. One of these is bubble wrap, in which air bubbles of a defined size and pressure are sealed between two plastic sheets. These materials are exceptionally light weight, with densities as low as 11 kg/m (0.7 lb/ft³). They are used in the form of bags and envelopes, as well as wrapping material. Bubbles are available in several different sizes, with larger sizes intended for heavier duty applications.
Taking this concept one step further, transparent inflatable bags can also be used to provide a cushion of air around the product, while taking up minimal space during shipping and storage prior to use.