The walls of many older homes are made of lath and plaster. If you put a nail in this material, it is likely to crack, flake off or create a hole bigger than you intended. To avoid this circumstance yet not compensate with bare walls, many of these older homes have a picture rail, or narrow trim that goes around the perimeter of the room a set distance from the ceiling. This picture rail is firmly attached to the wall near the ceiling. Pictures can be hung from specially-designed clips that attach to this picture rail.
Test that the hooks fit on the moulding of your picture rail. The hooks should fit snugly. This may require bending the hooks to the contour of the moulding because of build-up of paint or variation in the moulding profile.
Attach a metal loop or D-ring to the top two corners, the same distance from each corner, of the picture to be hung. Make sure the top of the loop doesn't extend above the top of the picture frame, but otherwise hang them as close to the top as possible.
Cut a length of wire 10 cm (4 inches) longer than the distance from the picture rail to where you want the top of the picture to be, using the wire cutters.
Wrap one end of the wire around the small end of one of the picture rail hooks in two to three tight loops, leaving about 10 cm (4 inches) of wire sticking out on one side and the longer length on the other.
Measure about 1.2 to 1.8 cm (1 inch to 1 1/2 inch) from the picture rail hook on the long piece of wire, using a measuring tape, and tightly wrap the shorter end around it several times to secure the loop on the hook.
Clip off any excess wire from the short end that was wrapped around the longer wire.
Repeat for the other hook.
Fit the larger ends of the picture rail hooks over the top of the picture rail about the same distance as is between the loops on the back of the picture to be hung. Let the wires dangle.
Hold the picture up about where you want it to hang and make sure you have enough wire. This is best done with two people.
Thread the loose end of the wire on the right side through the corresponding picture loop.
Pull on the end of the wire to adjust the picture to about where you want it to hang.
Wrap the loose end of the wire around the wire just above where it goes through the picture loop. Make sure it is secure enough to hold the picture temporarily.
Repeat steps 10 to 12 for the left side.
Adjust the picture rail hooks to the left or right until the wires are parallel.
Make more loops or take loops off the picture rail hooks to adjust the picture up and down as necessary. You can also adjust the height at the picture by unwrapping the wire and adjusting it up and down before re-wrapping.
Re-wrap the wires at the picture, making the wraps tight and even, and clip off the tail of the wire.
If you are concerned about the security of the moulding hooks, use a small nail or screw to put through the existing hole in the moulding hook. Be careful to not split the wood or damage the moulding hook.