I've used the plastic cutting boards and the corrugated plastic. Both work great, but I'm definitely going to try the self stick tiles mentioned above. What a GREAT idea!!

This is a great idea and can be found at the dollar store or Goodwill.

Stiff Purse Bottom Ideas
 

This is what my friends do - they found that foam core bent permanently when they carried something too heavy (in one case) or when someone banged into them/their purse at an odd angle at a quilt show (the other case) - so they came up with this double-plastic canvas idea, but they covered it with fabric for each removal (but if forgotten could still go through the wash).

I use mat board that is normally used by picture framers. My daughter is a professional framer and she gives me all her scraps. I cut them to the size needed, glue 2 pieces together, for strength, make a sleeve, to fit, from the purse lining fabric, slip the mat board inside and then it can be removed to wash the purse. If you have a frame shop close by ask them for their scraps.

I haven't tried this yet, but I've had friends use worn out cutting mats. Cut out the good pieces for purse bottoms. I haven't worn out any mats yet.

I use the Plastic canvas double & also make a sleeve for it & it holds up very well & adds no weight.

I was going to ask the same question!!!! I made one bag and it is way too flimsy...I thought about 1/4 inch acrylic from the hardware store. I love the idea of using floor tiles. The DH brought home a half box of the ugliest commercial floor tile I have ever seen, the cheapest stuff you could find. But it is perfect for a purse! Thanks!

I keep a look out for discarded plastic signing from local walmart. The signs are like cardboard but made from plastic. Just the right stiffness for the job. I got a real big one last time that will last awhile.

Wow!! Great suggestions. I haven't thought of a lot of these!

I stock up on plastic placemats from the Clearance Aisle at WalMart. I recently purchased about 30 for $.15 each. I also use them for templates. Heavier than template plastic and a lot cheaper.