Foams are substances, natural or man-made, that consist of many gas bubbles being retained in solid or liquid form. Substances like Styrofoam or packing foam differ in texture from liquid foam such as sea foam or foam from a cup of cappuccino. Foams dispensed from aerosol cans are generally used for insulation in buildings, but can work well for packing items in a container much like foam "peanuts", because the function is basically the same. Canned foam usually comes in two types; expanding and nonexpanding. Nonexpanding foam is ideal for packing because expanding foam may crush items or take up too much space.
Things You'll Need
Box or container
Place a plastic bag into the container that you will be using to ship. The bag should be large enough to fit in the container and drape over the sides several inches.
Spray the inside of the bag with foam, completely covering the bottom and filling it about one fourth of the way. Pick the box up a few inches off the ground and let it drop two or three times. This will set the foam evenly. Fold the remainder of the bag over the foam.
Place the items you're shipping into the box on top of the bag and apply a little pressure for a snug fit. The foam will "mold" itself around the shape of the contents.
Lay another large plastic bag over the contents and spray the foam over this to fill the box, filling the spaces and covering completely, to about an inch from the top of the container. Once the foam is dry, seal the package for shipping as usual.