Double curves are a type of geometric shape that consists of two curved lines that intersect each other. The term 'double curves' can refer to three different shapes: esses (5 letters), ogees (5 letters), and sshapes (7 letters). Esses are S-shaped curves that are symmetrical, while ogees are W-shaped curves that are also symmetrical. Sshapes are a combination of esses and ogees, with one side being an ess and the other side being an ogee. All three of these shapes are commonly used in architecture, furniture design, and other decorative arts.