Storing the Thread Storage

Now that title sounds redundant! Earlier, I showed you how I sort and label thread spools into different plastic carriers. Now.... how does one efficiently store those carriers?
This is not only efficient, it's inexpensive. What? in this day and age , something doesn't cost an arm and a leg? YEP! You know those prefabricated,put it together yourself bookcases, cabinets, etc you buy at Target or other such general merchandise department stores? For around $20, one can get a narrow 2 shelf pre fab. unit wherein each of the 2 sections holds 6 of the plastic storage carriers. Thats 12 carriers in not much more than 2 cubic feet. ...and it all fits underneath a table. Very handy.