Bentwood Block Set. The new way to round out creative classroom play. Create tunnels, arches, domes and skate parks for super-hero toys. fairy boats and bowers. These new bentwood blocks open a whole new world of possibilities for the imaginative young architect. Made from sturdy 7-ply hardwood with a smooth, natural oak finish. These blocks present new challenges in creative play, whether used alone or with our Empire Hollow Block Builder Set or our traditional block sets. Imported. Lifetime Warranty.