Great Idea, my son works in a pizza place- never thought to have him bring be unused boxes.
You'll love the 16" size to lay out all your cut pieces on to carry to the machine. I love using the boxes as a tray to transport the selected fabrics; it holds more than my arms can carry! lol. I also love the way the flaps are inside (and not outside) so they become more neatly stacked and no lost pieces. :D