It would be nice to have a texture similar to the current Edge Texture, but one that considers only the "external" mesh edges, or NURBS edges.
Currently when I need this effect I use a Grid texture fitted 1 to 1 to the surface. But unless your surface is a perfect square, you need to play with the dimensions to get the desired width. (Example below)

Currently when I need this effect I use a Grid texture fitted 1 to 1 to the surface. But unless your surface is a perfect square, you need to play with the dimensions to get the desired width. (Example below)