Hi Brash - a closed surface will always have a "seam edge" - that's just how NURBS surfaces work. The surface is defined by a rectangular grid of control points, something like a sheet of paper. But it's a stretchy rubber sheet of paper and some spots (the ends) can be pinched down to a point, and you can also make a closed tube by rolling up the sheet of paper so that 2 opposite ends touch each other, that's what results in a seam edge.

The particular profile that becomes the seam depends on the order that the curves happened to be processed inside of the command's calculations. In some commands if you individually click on curves that can affect the order that they are processed, I don't remember right now if that is the case for Network or not.

- Michael