Curveline Inc., Ontario, Calif., offers curved 3-inch trapezoidal standing seam roofing panels for commercial and residential applications. The curved panels combine attractive shadow lines with a leak-proof design that overcomes the water infiltration problems sometimes associated with shallower, flat pan (vertical leg) curved standing seam. Three-inch-deep standing seam panels may be curved into radii from 30 feet to 350 feet using Curveline's proprietary method. In addition to aesthetic benefits, the curving process also enhances the strength and rigidity of the panels, further increasing their spanning capabilities and minimizing the structural support requirements. Panel widths of 12 inches, 18 inches and 24 inches may be curved. Substrates best suited to curving are 26- and 24-gauge galvanized or zinc-aluminum-coated steel, although Curveline can also curve .032, .040 and .050 aluminum.