O.D. Arches:

O.D. arches are used in windows with very slight arches. The top rails are made wider to accomodate the arch, and the outside diameter is cut into the wider top rails. This application is less expensive than the I.D. arch, as no louvers have to be shaped to fit the inside diameter of the arch.
O.D. arches can be any configuration of panels. One, two, four or six, etc...and are usually used in windows that have a arched space of 12" or less.
Also in this category would be the step up arch. Each panel has a different rail width, but the louvers are set to go up into the arch as much as the radius allows. So in a four panel opening, the two outside panels may have less louvers than the two inside panels, as the extra height of the two inside panels allow for more.

Custom Shutters can manufacture ANY size or shape shutter imaginable. Please call us at 1-800-944-1021 with any questions or for a no-hassle quote on your next project.