The pattern calls for either Annie's Soft and Stable (which is kind of pricey and not available to me locally) but Sara also mentions that she had a tester recommend "Automotive Headliner fabric." Touch the ceiling of your car- that's it! I was shocked to see that my local Joann's carried it and even more pleased when I saw how well it worked and how user friendly it is! I didn't break a needle once and it all came together really easily.
Another new-to-me notion the bag requires is an "invisible magnetic snap." My Joann's does not carry this and I didn't want to wait for an online order of some to arrive in the mail. I sent my husband to the hardware store on his way home from work to pick up some magnets and I sewed four of them into little pouches with some scrap fabric. I attached them to the headliner fabric pieces as directed - making sure they wouldn't repel each other- and it worked great.
The interior of the bag features a padded pocket for an electronic device and an interior zippered pocket. I used some Kona Berry I had in my stash for the lining.
I love how striking this bag is and what a unique bag it is compared to your average tote or purse. I will definitely make this one again.