Originally Posted by Jim's Gem
There is a new product out. For the life of me I cannot recall the name of it. It is very similar to the "headliner" stuff they use in cars. It is stiffer than batting, kinda like a thin foam that works wonderfully in bags and such. I'm sorry I can't think of the name. I had a flyer I picked up at Long Beach International Quilt show and I can't find it at the moment.
It is called Soft and Stable. I have some but haven't used it yet. Google the name to find the website.
Another suggestion for such a big bag is to do the same as you did the last one and then when the panel is made then add a layer of fusible fleece to the back of the panel.
I sometime use 2 layers of fusible fleece when I want something good and stiff.