sunnybee
cardboard? usually, drawer bases are plywood that slots into grooves at the sides, available at most diy centres. if you are looking for cardboard, try a large arts and crafts centre or this company (uk) but how is cardboard strong enough as a drawer base?

stew575
As mentioned before, mose drawer bottoms usually use a 1/8 or 1/4 inch thick plywood board or sheet. Wood would be preferable for it's rigidness and strength. the plywood would resist water or moisture damage.

Tom Sullivan
Greetings, My name is Tom, and I am with Home Depot's "How To Community" found at the link below. As other posters have indicated, what you are referring to as cardboard, is actually Masonite, a type of pressed hardboard that is typically used in those applications. Home depot carries it in my area, and many DIY stores should as well. You may find that after removing the drawer front, you can slide a new piece of Masonite that has been cut to size and replace the bottom easily. I hope that helps.

classicsat
You want 1/4" or more plywood. Sometimes they use what is sold under the brand name masonite, which is a pressed wood fiber product. Home centers have either, and can likely cut it to size for you.

Odioso6767
We're gettin better man! :)