Shutter dogs come in many different shapes and sizes. The most popular of shape is the s-pattern (shown in the picture). Other shapes include stars, shells, flowers, and grapes. The shutter dog rotates horizontally to allow the shutter to pass and vertically to lock the outdoor shutter in position.
Functional exterior shutters must be constructed from a solid material. Wood shutters are the most common shutter used on homes all over the world. Some solid composite shutters are available, but are very heavy and expensive.
Shutter dogs are most often forged from cast iron. They are extremely sturdy and should last the entire life of any house. Most shutter dogs have a black finish. There are vinyl shutter dogs available that can only be used with decorative vinyl exterior shutters.