"Not welding gives 2 single sided faces without any shared vertices."
It does not make it single sided.
"Not welding gives 2 single sided faces without any shared vertices."
I have to go out for a while but, Are you sure about that?
Yep
I don't see that. Frozen from left to right is single sided nurbs, double sided welded, double sided not welded and last is the original plane. Views are from above and below. Both the tS plane and the single sided nurbs plane are invisible on the backside. Only visible because I have edges turned on.
Okay?If you have a double sided nurbs it will have a double sided look when converted, welded/healed or not.
Maybe something like this,
That sounds goodHeal Vertices?
Selecting No will create a mesh with unconnected geometry