cube out

To fill the entirety of a storage area or space with boxes or cube-shaped containers, especially when they fit perfectly together without leaving any gaps. A noun or pronoun can be used between "cube" and "out." Ideally, you'd want to cube the pallets out before wrapping them up to avoid things shifting around during transport. We want the boxes to be as densely packed as possible when cubing out our cargo ships. We aren't paying to ship air, after all.