"Package cushioning is used to protect items during shipment. Vibration and impact shock during shipment and loading/unloading are controlled by cushioning to reduce the chance of product damage.
Common types of cushioning
Loose fill – Some cushion products are flowable and are packed loosely around the items in the box. The box is closed to tighten the pack. This includes expanded polystyrene foam pieces (Foam peanuts), similar pieces made of starch-based foams, and common popcorn. The amount of loose fill material required and the transmitted shock levels vary with the specific type of material.
Paper – Paper can be manually or mechanically wadded up and used as a cushioning material. Heavier grades of paper provide more weight-bearing ability than old newspapers. Creped cellulose wadding is also available. (Movers often wrap objects with several layers of Kraft paper or embossed pulp before putting them into boxes.)
Corrugated fiberboard pads – Multi-layer or cut-and-folded shapes of corrugated board can be used as cushions.These structures are designed to crush and deform under shock stress and provide some degree of cushioning. Paperboard composite honeycomb structures are also used for cushioning.
Foam structures – Several types of polymeric foams are used for cushioning. The most common are: Expanded Polystyrene (also Styrofoam), polypropylene, polyethylene, and polyurethane. These can be molded engineered shapes or sheets which are cut and glued into cushion structures. Convoluted (or finger) foams sometimes used . Some degradable foams are also available.
Foam-in-place is another method of using polyurethane foams. These fill the box, fully encapsulating the product to immobilize it. It is also used to form engineered structures.
Molded pulp – Pulp can be molded into shapes suitable for cushioning and for immobilizing products in a package. Molded pulp is made from recycled newsprint and is recyclable.
Inflated products – Bubble wrap consists of sheets of plastic film with enclosed “bubbles” of air. These sheets can be layered or wrapped around items to be shipped. A variety of engineered inflatable air cushions are also available. Note that inflated air pillows used for void-fill are not suited for cushioning.
Other – Several other types of cushioning are available including suspension cushions, thermoformed end caps  , and various types of shock mounts."