cloth polygon question

[betrayer_requiem]

In that Basic Art Guide, there is a line said "Polygons are single-sided (the backsides of the polygons are invisible). When making a thin piece of cloth, it needs a front side mesh and a back side mesh, even if it has 0 thickness. "

I just clone the single-sided cloth, flipping the normals of the clone,is that ok?

or do I need some more steps?(like welding some point?change what edge to soft or hard of this cloth?move the clone or just make coincidence with the clone and the original?)

I really want a 0 thickness cloth of my work,and this 0 thickness cloth should have cloth physics ,plz help