found at Tentworld
Designed specifically to fit the footprint of a Coleman Instant-Up 6-Person tent this grounbd sheet with 450D PVC anchor patches for added strength is a handy flooring addition when you want to keep your tent space clean and dry. Sometimes referred to as a footprint, ground tarp or floor saver, ground sheets exist to protect the underside of your tent & furniture against everything that nature throws at it from the ground up.
The ground sheet is made from a heavier-duty, shade-cloth type material which is easy to fold and pack away at the end of your outing. Its UltraMesh design allows the grass underneath to breathe and lets dirt, sand or grit to fall through to the ground below before it ends up inside your bedding. It also ensures that the tent floor wont start pooling with water if it rains. In some unpredictable situations it can even serve an alternate use as an emergency wind breaker or hail shield.