To create a new curve from a surface component curve

1. Select an edge, isoparm, or curve-on-surface.
2. Select Edit Curves > Duplicate Surface Curves.

   When construction history is on, the curve remains linked to the original surface. Transformation is relative to the original surface, and changes to the component curve from which it was created change the duplicated curve.

   Tip

   You can duplicate an isoparm and use it as a wire deformer for the surface.