I have a bolt of Pellon decor bond, which is 45" wide fusible stabilizer, and I used it for making purses, which would help to give your cosmetic bags more stability, however there is a much thicker bond, but I do not know the name of it. I have a sample I would be happy to send to you. Please send me a PM on QB and I will get back to you. Put cosmetic bags in the subject line.

I really like headliner fabric for bags that need to stand up. It's quiltable, soft, but has form. JMO

I make a lot a zipper pouches. The first thing I do is interface all the pieces with Pellon SF 101. It gives body to the quilting cotton. Then I use fusible fleece on the main body pieces, over the SF 101. Do not use the fusible fleece on the lining pieces. It is too much. I then box the bottom corners. They come out with just the right amount of stability, yet can be easily folded for storage.

I purchased some Deco Bond at Walmart last night, but haven't had time to use yet. I plan to purchase some of the headliner material from Joann"s as soon as I get my next coupon in the mail. I really liked the Pellon Flex Foam I purchased, but think it was an overkill for a pouch---a larger bag, yes, so maybe Joann's headliner will be "just right".

Quiltmaker: Which fusible fleece would you recommend using with the interfacing? Here is a link to Walmart page for the fleece. https://www.walmart.com/search/?query=fusible%20fleece
I was there last night feeling everything, and there is a wide differential in them.

I use Pellon 987F in all my zipper pouches and all the bags and purses I make. It is important to use the Pellon SF101 first. I can’t believe what a difference that makes.