Copy of Box - Folding for Maximum Volume

How can we make a box with maximum volume from a given size "blank" of material? (This is a modification of Dani Novak's excellent demo)
You are given a "blank" of cardboard and asked to make a box out of it, that has the most possible volume. You make the box by cutting squares of side from the corners, then folding the "flaps" up to form sides. (The top stays open).