Why a 2-Point Hanging System?
Traditionally, frames are hung on the wall with a wire over a single nail or hook, but there are many shortcomings of this method. It places tremendous tension on both the wire and the wire anchor points on the frame. The tension will often break the wire, pull out fasteners, split the frame, and/or bow the sides and top of the frame. Any of these outcomes can result in damage to the art within the frame and to the frame itself. Furthermore, if the wire is tight across the back of the frame, the forces on the wire and each anchor-point can be as much as 14 times the weight of the frame.
When using a single hook in the wall, regardless of the frame size, the wire is rarely allowed have more than a 15 or 20 degree angle up from horizontal, which causes the forces on the wire and anchor-points on each side of the frame to be more than 2 times the weight of the frame. On the other hand, by using 2 hooks in the wall and adjusting the wire so it rises to the hooks at a diagonal or near-vertical angle, the stresses on the wire and anchor-points are decreased to slightly more than one half (1/2) the weight of the frame at each wire anchor point. Forces directed near-vertical on the wire anchor-points minimize side forces on the frame, thereby reducing forces on the artwork/glazing package.
We can calculate the stress placed on a hanging system by determining the angle between the wire as the frame hangs and an imaginary horizontal line drawn between the two anchor points. Notice that 15 degrees is the most we can reasonably get if we hang the frame from just one hook. Below is a typical rear view of a frame with the anchor-points on the vertical sides of the frame approx. 1/3 down from the top of the frame. The 15 degree wire angle is common practice, although many framers attach the wire even more tightly.
The laws of physics show that for any 10 lb. frame with the wire attached 15 degrees up from the horizontal, the resulting force pulling on the wire from each anchor-point is 19 lbs. The force increases as the angle decreases and decreases as the angle increases.
A common problem (in addition to stripped-out screw eyes, split moulding, and broken wire) resulting from a wire positioned too near to the horizontal is the top of the frame bending upward as a result of the wire forces. The next drawing is slightly exaggerated to illustrate the problem. With 19 lbs. pulling toward top-center, each side of the frame is pulled inward until stopped by the artwork/glazing package. Then, the top of the frame will usually bow upward as the sides are drawn together and bent inward. Since gravity usually ensures the artwork/glazing package is resting on the bottom frame leg, bowing of the top frame leg can expose the top edge of the glazing.
This is why my general hanging method is to attach the wire at such a length that when the frame is hung from 2 hangers the wire is between 60 and 45 degrees up from horizontal. This procedure significantly reduces the forces mentioned above as well as ensures the frame will hang level. While there are numerous other hanging methods and commercially available hanging systems that allow frames to be hung without stressing either the frame or the art (cleat systems like Z-Bar and Hangman Hangers and other 2-point systems like Wallbuddies), a longer wire suspended by two hooks is easy to install and easy to level, while also keeping the frame from wobbling like a single hook would, plus it keeps the frame flush to the wall and not dangling forward.
Where do you hammer in the hooks?
First, find the distance between the hooks
With the frame face down on a table and upside down, you should be able to pull the wire with your two index fingers far enough apart that the angle of the wire down from the anchors is at least 45 degrees and there’s a straight segment between them. With the other fingers of your right hand, you should be able to place a ruler or tape measure along the wire to measure the length of this straight segment between your index fingers. For each frame I write on the small instruction sheet in the bag with the hooks the recommended distance between the hooks which should give this 45 – 60 degree angle from the anchor to your finger as you pull the wire tight. If you choose to use a different spacing between your hooks, read it off the ruler and make note of it
Now, measure from the wire to the frames’s top
The next measurement is a little like tying a bow. First, with your left index finger, instead of pulling the wire straighten your finger and hold the wire in place, pressing it down to the back of the frame. Now you can release the right side of the wire with your other hand and use the ruler to measure from the place the wire is being held by your left index finger to the top of the frame, which right now is down toward your body. This is how far down from the top of the frame you will need to place the two hooks on the wall.
Establish the frame’s placement on the wall
Place the frame on the wall where you want to hang it, and, possibly with the help of another person, make a tiny dash with a pencil on the wall at the top of the frame in the middle. This dash should be drawn light enough that you can erase it from the wall, but unless you’re hanging it very low a viewer of normal height won’t see it up there. When hanging a grouping of frames where placement is critical, I like to cut sheets of brown wrapping paper to the full size of my frames so I can place them on the wall and fine tune the layout. Then, just make your tiny pencil dash just above the top-middle of the paper.
Measure down and across to find the hook placement
Now you need to use your ruler to measure down from that dash the second number you measured, the distance from the wire where your finger held it to the top of the frame. Once you make another dash there, draw a tiny vertical stroke to make a plus sign. Now, divide in half the distance between the hooks from the first measurement and measure that 1/2 distance on either side of the plus mark and make another small vertical mark with your pencil. This is where the bottoms of the two hooks should be when the nails are driven into them.
Hang the wire on the two hooks and level
For heavy frames, the included hooks might need two or even three nails. The imported Ziabicki Floreat hangers I include cradle the nail, keeping it at the proper angle as you gently tap the nail into place. The nails are thin, extremely sharp and made of tempered steel. These hangers are especially suited for lath-and-plaster walls. The head of the nail is brass to cushion the hammer taps, with knurled sides for traction so that if needed you can pull it out with just your finger and thumb. And don’t stress over whether the hangers are perfectly level – the wire can be slid side to side along the two hooks until the frame is level. just hold the wire between your fingers as you hold the frame from the front and feel for the hooks, pulling the wire down over one, then the other hook. Between the two hooks and the rubber bumpers on the bottom corners, your frame should not move out of level once you find it.