Anticlastic refers to a specific type of curvature in geometry and material science. It describes a surface that curves in opposite directions along two perpendicular axes. Essentially, if one axis of the surface curves in a positive direction (like a hill), the other axis curves in a negative direction (like a valley).

For example:

• A saddle is a classic anticlastic shape. Along one direction, it curves upwards, and along the perpendicular direction, it curves downwards.

• Contrast this with synclastic surfaces, like a sphere, which curve in the same direction along all axes.

Anticlastic surfaces are often encountered in architecture, sculpture, and structural design, as they provide unique aesthetic and structural properties. In metalworking and jewelry-making, the term describes the shaping of materials to achieve this type of curvature.