Up North

I use the self stick floor tiles . I out two pieces together and make a sleeve or just one leaving the paper on it.

dmyers

Wow that's a cute bag!

Crqltr

I have used foam type poster board, sturdy and very light weight. Hobby lobby has it

OneMoreQuilt

Beautiful bag ..... and welcome from Illinois,

NanaCsews2

If you have old school or office binders (the ones with the cardboard and covered in vinyl) not being used, measure the bottom of the purse and cut out a rectangle from one side of the binder. Sturdy, and a little waterproof too. Cover with coordinating fabric that is removable and washable.

Xstitshmom

I have used matte board that you use for framing pictures.

Annaleehunter

I love your bag!

BMP

I used 2 layers of the plastic canvas and put them in a envelope style covering made from the lining fabric.

angiecub

I too use the foam core board. I've found it at Wal-mart.

maine ladybug

I have used wood,plastic ( the kind people use for counted cross stitch ) and my new favorite is the heavy packaging stuff that comes in a package of meat. I wash it well, let it dry and cut it to the size I need. Then I cover it with fabric and stitch it into the bag bottom. Works like a charm and it's free!