IrishgalfromNJ

These are called bag-e bottoms by lazy girl designs made for purses and totes.

http://www.lazygirldesigns.com/produ...bottoms-size-a

DonnaC

In addition to the plastic canvas (and yes, I do use more than one sheet for durability), I've used the plastic cutting mats (for food) that you can buy at the Dollar Tree. Those can also be stacked and cut to size. I have also used the foam board which works great.

In a pinch I've cut up boxes that come in the mail. Waste not... want not!

RainyBC

Browsing around our local builders store, I found a strip of rigid plastic 4 1/2 inches wide that is used for leaf guard to cover house gutters. It does have holes in it but is still quite sturdy. Heavy duty scissors are needed to cut it. So far, this is the best thing I have found after trying several other options. It's also the cheapest, or should I say most economical.

Pam B

Actually, I've used the heavy cardboard like from boxes athletic shoes come in and covered them with fabric. That works well for purses. Obviously, you might want something sturdier for larger tote bags.

PaperPrincess

Check at your local sign shop. Ask if they have any scrap plastic, usually inexpensive, sometimes free! You can also use a piece of foam core, but put it in a sleeve so you can replace it if needed. Works well & light weight.

Knitette

Me three, lol!

pattypurple

the corrugated plastic that they use for election type signs works well. I get it from my local sign shop. Just asked for their scraps. I cut it with an old rotary cutter. It is light weight, but sturdy.

ann31039

I use the Corplast (sign material) sometimes and the foam core boards also. Dollar Tree carries them. The large ones for a $1.

Kat Sews

I use heavy peltex because I want my bags to be washable without taking the bottom out.

Julienm1

Wow thanks for all the idea guys!!