Canvas tops can get waterproofing | Truck top, Truck covers, Big trucks
Canvas Bed Cover - Pack for 2 1/2 Ton Cargo Truck (BKM2191) - Brickmania Toys
Tarp Canvas,Heavy Duty Waterproof Tarp Outdoors Canvas Tarps Truck Tarp Water Resistant UV Resistant Tarpaulin Cover for Car Boat Camping Firewood Woodpile(6.6 x 6.6 Feet) - Amazon.com
Amazon.com: YXX Green Canvas Drawstring Tarp with Grommets for Truck Bed, Carport& Above Ground Pools- Heavy Duty Waterproof 34 Mil Tarpaulin for Outdoor Cover (Size : 5x8m/16.4x26ft) : Patio, Lawn & Garden
Source Canvas and polyester Car tonneau cover for light truck made in Japan on m.alibaba.com