Local sports venues usually aren't built for comfort. Protect your end zone with a bleacher cushion made in the colors of your favorite team.
For each seat, stack three mailers and tape the edges together with duct tape.
From the vinyl tablecloth, cut two rectangles about 1 1/2 inches wider and longer than your envelopes. Seal three edges with duct tape, leaving one of the short sides open. Slide the stack of mailers inside the tablecloth envelope, then tape it closed.