Polyethylene (PE) Foam is a closed-cell foam that is durable and provides excellent cushion capabilities. It floats, you can wash it, it does not absorb moisture, and it is impervious to most chemicals. It does not do well in the sun, however! You can use a heat gun to weld it to another piece of PE foam and you can cut it with a jig saw. This is 1.7 PCF Foam.