They come in sets of threes. I like the look of these Ballard Market Nesting Baskets, and I think this is a good buy for three. You could keep art supplies in the small version and sketch pads and loose toys in the larger one.
Market Nesting baskets are made from water hyacinth and were designed with sturdy metal frames to hold kindling, laundry and other bulky items. The handles make it super easy to carry the things you need.
Small: 11 3/8"H X 19 3/4"W X 10 3/4"D
Medium: 15 1/2"H X 23"W X 15"D
Large: 19 1/4"H X 26 3/4"W X 18 1/2"D — Between Naps on the Porch