meanmom

I use plastic canvas. Sometimes one or two layers depending on the size of the purse.I cover it with fabric. I have even forgotten and run it thru the washer and dryer and it was fine

puck116

I've used painter's canvas found at your craft stores like Michael's. Cut it with a saw to what ever size you need.

roxie623

I use artist canvas (used to paint on) cut to size and make a sleeve for it. Nice & firm.

Stitchit123

I found sheets of what looks like cardboard but its plastic in the craft aisles at HobbyLobby type stores-and I use it for Q/patterns too I wait for a coupon sale and grab it then then its 2for1 I never thought to look at JoAnns for it cause I found their prices on craft stuff higher even w/coupon Oh if you have a Michaels near by they have it also

KS quilter

I made about a dozen of them a couple of years ago for gifts.
I did what one of our gals in our quilt guild did. She went to
Walmart and bought a plastic (vinyl or whatever) place mat.
You can cut them easily. If they get wet, won't ruin them
vs. what a paper product would do. I made an 'envelope'
out of fabric slid in the cut piece of mat, and folded under the
open end and put it in. If you ever want to launder the purse
you can take it out. I also do that for totes, etc. I thought
she was pretty clever to think of that.

brosier

I use 2 pieces of heavyweight cardboard - the kind that is corrugated, but less than moving boxes,= smaller corrugations.
Then, I cover it with fabric and and stick it in the bottom of the bag. Works well, and it's cheap.

jitkaau

I cut up the plastic beading mats (the ones with the holes in them) to fit the size of the bag bottom.I think they are called plastic canvas.

Birdena

I buy those think plastic cutting boards from the dollar store then I can cut them to any size needed.

GGinMcKinney

I use plastic canvas. I can easily cut it to fit any size tote bag. I cover it in fabric to match the lining. Sometimes I sew it between the lining and the exterior bag other times I make it removable.

Grandma58

I use nothing.