Step 2: Sticking part
1. Put one box as a base.
2. Put a glue on 2 sides of the box and stick another two boxes on it.
3. Glue the back side of base box and two side boxes.
4. Add another box between those two boxes. (you don't need to add this one, but the rack will be much more stable with it )
5. Glue all three top parts of boxes.
6. Add another box on the top.
First deck of the rack is ready.
Step 3: Making more decks
You can add as many decks as you need :-)