diy-vs-prohanging
I have dozens of pieces of unframed artwork. I would like to hang them on the wall, in a way that is somewhat easy to rearrange. I'd like them to line up horizontally, and to be against the wall so they don't swing/flap as much when the room's ceiling fan is on.
I have in mind to simply buy a long piece of wood and glue a few dozen tiny clothes pins to it. I'm hoping there is some better / nicer / easier solution.
At Home Depot (or Lowes) you should be able to find these Spring Loaded Mirror Mounting Clips made specially for hanging a mirror. They are no where near as big as a j channel and the top two have a small spring inside of them so they kind of grasp the mirror (and snugly fit on the glass).
You put the two without the springs in the bottom and the mirror just sits in them. Two more (with the springs) added to the top prevent the mirror from falling forward. Of course it would be best if you can get them into a beam in your wall. And you will barely notice the clips on the mirror once it is in place.
Just because you can't see the joists doesn't mean you cannot use your beam approach for exposed rafters. The structure is essentially the same, except for a thin layer of sheetrock between the two, which has little impact on the forces involved. The best thing to do is distribute any concentrated load over multiple connections. Use a flat 2x4, or better yet 2x6 that's long enough to span 4 joists, about 4 to 6 feet. Place the chair connection at the center using a large through eye bolt, using an over sized washer to spread the load into the wood. The nut and bolt end will end up punching into the ceiling, but that's OK. Holes are easy to patch if the beam is ever removed, otherwise, it doesn't show anyway.
Attach the 2x beam to each joist with two 1/4" dia. lag screws. Use a screw long enough to penetrate 2 inches into the joist material, probably 4 inches. Drill a 5/32 inch pilot hole before placing each lag to prevent splitting the joist. The resulting 8 screws is more than adequate to support any adult and will not significantly weaken the joists.
Best Answer
You could try painting it with a magnetic paint and use those strong small earth magnetics to hold the art up. The magnetic wall paint can be top-coated with a single coat of whatever colour you want.
There are a number of paints from different manufactures to choose from, some with better reviews than others. It seems multiple coats are needed, but other people report success. Strong magnets are a must.
I have not used this myself, but I have seen it used in a number of design magazines, etc.