A simple standoff for hanging backlit art. This standoff has a void that takes a 20.4mm x 3.05mm (.79"x.12") Neodymium Magnet. The thin lip around the top of the void allows for the magnet to just snap in, rather than needing glue to secure it. 

First, secure it to the wall using a #8 Pan head secured to an anchor, then just snap in the magnet. To attach the the other magnet to your artpiece, secure as many standoffs as you need, snap in the magnets, then secure the magnet that will be attached to your art piece to the magnet in the standoff. Apply a bit of ink or transfer marking to the top magnet, and press your piece against it to mark where the other magnets should be secured to the back of your piece.

Once marked, glue the magnets in place, and voila.