Funko Pop! stadium shelf brackets

A modular shelf bracket to support precut finished wood planks (3.5" x 0.5" x 3'-0" Poplar from the home improvement store) for storing my Pop! collection on top of a bookshelf. I have tested this in 2, 3 and 4 shelf configurations. Print one pair of the first bracket for each shelf but the last, print one pair of the second bracket for the last shelf.