DIY Waterproof picnic/park/beach blanket. Sew a large piece of heavy material (I got mine at value village for $4) and a vinyl tablecloth (can be found at Dollarama for $2) right sides together leaving an opening about 2 feet. Turn right side out. Sew again around the edge with a 1 cm seam allowance. While sewing around the edge, sew the opening shut. I would assume you can wash this in a gentle cycle, but do NOT put in the dryer!!!