It's very confusing out there. I think I'm going to use non woven fusible and non woven cut away interfacing. The fusible was water proof until it got soaked, I was actually able to hold water in a sample I made until I squished it around a bit. It can be washed but not removed. So I'm also going to make one without interfacing and use the non woven/non fusible as an insert. I'll give them both to my daughter to try.