The air in the atmosphere is being pulled down by gravity. This creates atmospheric pressure at the surface of the earth. So, for every square inch of skin you have, the atmosphere pushes in with a force of 15 pounds. This means that there is no total force, and so nothing happens. For the closed-cell foam, a piece of styrofoam works, but this material is stiff.
Squishy foam is better.
Open-Cell Foam 1. Take a piece of open-cell foam and put it in the small garbage bag. Insert the nozzle of the vacuum cleaner into the bag, and gather the bag around the tube so that it makes a good seal. After you have a good seal, turn on the vacuum. This is actually a good, practical technique for storing foam and other porous articles, like clothing.