Stabilizer is a material you use to, well, stabilize fabric when you do all types of embellishments, which can be as fancy as machine embroidery or as simple as a zigzag around an applique. Simply stated, it helps to hold your fabric flat to keep it from bunching up under the stitches. Many types wash away, so it's not really meant to add permanent stiffness to an item.
Interfacing adds permanent stiffness, body or thickness. It can be sew in or fusible. The final product can be soft or very stiff. If you really want something very stiff, Peltex or Timtex are good products, as is a heavy home dec interfacing, like decorbond. but I agree with Sewbizgirl. Do you really want stiffness or just body? Soft & Stable is a great product that will make your cover stand by itself, but will still be soft and light weight.
You probably would not want to also use batting with a heavy interfacing, but you could just use warm and natural and quilt the heck out of it with a heavy thread. Folks are always complaining about too much quilting making the quilts stiff.
Another product to consider is a fusible fleece.
Look online for free tote bag videos for other tips.
Last edited by PaperPrincess; 03-11-2017 at 03:20 PM.