Interfacing material for a PV material

[ccga3359]

I am working on a kilt made of PV (Polyester Viscose or Polyester Rayon). I usually use hair canvas as the interfacing but hair canvas is not machine washable. So, what should be used if you want to keep the machine washability of the material?

Hair canvas is pretty thin compared to the interfacing you can buy at Joann's. What should the weight of the interfacing be?

Wallace

My PV CCK's aren't interfaced. Do you need interfacing? Could you not use the same material for that?