I've made a dresden plate with ties, and put (too stiff) interfacing on the foundation, then I quilted a starburst. If I also put stiff interfacing on the borders, why would I need batting? The binding would be wierd, but would that work?

I use felt when i want more body, it works perfect for wall hangings, has a sharp flat look to it, with depth.

I have seen wall hangings without batting. I have also used fusible fleece or something like that to put as a substitute for the batting and then use no backing. Just a thought.
Remember whatever you prefer will be perfect. :)

I do the same! The felt gives the dimension to the quilting stitches, but more structure than a batting.

I actually tried the Waffle Muslin...Love it since it's a nice weight and looks nice for the back

If you use felt, can it be washed?

Why not use a thin, fusible batting? I hate fusible batting for larger projects, but it works fine for small wall hangings.

Not all felt is made the same... I have had great luck with some...tested it in a few potholders.. so do pre test the felt you are thinking about. it definately dries much faster. In a way its like batting not all are the same. I did get just a bit of shrinkage but other than that it washed and stayed just like it came off the bolt.