A Denver company manufactures high-quality tarps that can cost signficantly less than comparable products sold by competitors. What’s the secret? The tarps began life as large vinyl billboards and ended up at Repurposed Materials Inc., Denver, Co., instead of a landfill. The tarps are 20 mils thick and made of three-ply material, a polyester mesh (giving tarps a little stretch under high wind conditions) sandwiched between two layers of PVC. The tarps come in sizes up to 14 by 48 feet, are waterproof, anti-mildew, flame-retardant and have a UV coating for sun protection. They feature three-inch pipe sleeves, no grommets, and come in white or black (on one side); the other side might be a billboard for beer or laundry soap, but the ad side is required to be face down in use.