The Sonotube Commercial grade concrete forms have a woven plastic design that makes them more durable and more water resistant than paper. Resistant to jobsite abuse, the product can stand up to full liquid heads up to 20 feet. The forms won't rust or warp and can be easily trimmed on the jobsite. Lightweight and easy to maneuver, the forms don't require cranes. Sonoco. 800-377-2692.