BANKERS BOX Classroom 9 Compartment Cubby Storage 16" H x 28 1/4" W x 13" D (3380701)

What size are the individual cubes?

Would construction paper fit in compartments?

Where do I find instructions of how to put it together?

I have two questions: Is it open or closed at the back? Will a box that is 4 1/2" high fit into the compartment? (not worried about width or depth)