Fluffbuff

To answer your question about bag frames, they are plastic canvas shells that are used as the underlying structure for free-form crochet bags. The frames are meant to remain in place after the covering, and I suppose crochet is only one of the possible covering techniques, although it seems to be the most advertised by the frame sellers.

This is the inside of my friend's crocheted bag in progress. You can see the black frame underneath. This particular item is made in Japan.

It took some work to find online vendors, mostly because I didn't know what terms to use for my search. I didn't get many results using the strings "bag frames" and "plastic canvas", which seemed like a good starting point to me. I had better luck once I started using the terms "purse" and "plastic mesh".

Here are some online vendors; you can see pictures of the frames on these websites.

Lacis sells bag, purse, and hat frames:
www.lacis.com

This Australian website sells two kinds of bag frames:
www.threadsandmore.com.au

One bag frame here with a photo showing partial crochet work:
www.trimsandembellishments.com

and another Australian vendor with one kind of bag frame:
www.punchwithjudy.com.au

A while back I had seen other models on different Japanese websites, but I must have forgotten to bookmark them and now I can't find them. If you know of other sources, would you let me know? I have a couple of friends who would like to find out. Grazie!