Tarps are used to cover items so that they don't get wet from the rain or even to help give shade from the sun. Blue color tarps are generally used as an economy color tarp while silver color tarps are used as a more heavy duty type tarp. Tarps are also used in many cases as an emergency shelter where ones home has been damaged from the weather. Sizes of tarps range for 5' x 7' to 100' x 100'