Craig Smith of the Firefly Workshop writes in:

I had a $5 microwave cart from goodwill that ended up in my shop as a finishing table where I would paint, stain or varnish items on newspaper. It was bugging me that all the space underneath was unused, and my paints, stains and varnishes were in 3 different places on shelves. Based on a 20 minute sketch, the cart storage insert was made in one afternoon with scrap plywood I had lying around. Now my 32 cans of spray paint, 17 quarts of stains & paint, and 7 half-pints of paint are neatly stored under the roll-out cart for convenient use and out of the way storage.