I use warm and natural for my lap quilts but it's too flimsy (or so I think) for wallhangings. Is there a stiffer batting to use for wallhangings?

For some wall hangings I have "backed" the warm and natural with a stiff interfacing, and then handled the batting as a single unit , using a regular backing fabric. You can use fusible interfacing , but I spray basted my interfacing to the batting.

I use Pellon Fleece from Joanns. Much firmer than batting

You can always add a piece of interfacing (stabilizer) in your sandwich. Some are as stiff as cardboard!

Depending on how large your wall hangings are.... I had purchased a roll of Stiffy from Long Creek Mills http://longcreekmills.com/location.html and used nearly all of that for making wall hangings and whatnot. It's a lot cheaper than what you can get in the stores and it is quite nice I also would add a thin layer of batting to add depth to the wall hanging as well

I've used both Fast2Fuse and Decor-Bond for wall pieces....quilted the top onto the F2F and then just fused the pre-sleeved backing on and added the binding. Easy.

You can use Inn-Control by Innovative Crafts. The batting is also machine washable.

I forgot to mention that the Inn-Control is a cross between batting and foam.

Quilter's Dream "Deluxe loft cotton batting" makes nice wall hangings.