A picture hanging kit often includes the necessary hardware to hang your frames on the wall securely. The security of the hung piece is dependent upon the strength of the assembly. A simple slip knot will not be able to support the complete load bearing of the recommended picture hanging wire. It ought to be taught, have some slack to allow for levelling, but not be so slack that it risks failure.
Much of the security of hanging wire is based on a sturdy knot. Books have been written on the subject of multiple types of knots, each for different purposes, but for simple frame-hanging kits, one stands out above the rest.
The Improved Clinch Knot
The improved clinch knot is the way to go with steel-grade picture hanging wire. To make it easier to work with, use a pair of needle-nose pliers and wire cutters to cut the wire.
It should be noted that the position of the d-rings or eyelets is important to get right. They ought to be placed a third of the way down from the top of the frame, one on either side. An awl can be used to make a starter hole ready to drive your screw into the frame. Alternatively, use a narrow drill bit to pre-drill the hole before driving the screw into the frame, being careful not to split the wood.
Once the hardware is in place, next is to attach the hanging wire. Feed it through both d-rings and leave at least 3-inches to work with on either side (more if you feel you need it because it can always be trimmed).
Feed the wire through the ring, then wrap it around the wire five or six times beneath the ring. The thicker your wire is, the fewer wraps you will need.
After five or six wraps around the long length of wire, you should have what looks like a coil. Take the end of the line and feed it through the loop beneath the ring, then through the loop created between the bottom of the wire and the top. Pull that tight to close it, then use your pliers to push the twisted wire upwards toward the knot. If you have any loose wire left, you can snip it off, or wrap it around some more for extra sturdiness.
The improved clinch knot is one of the sturdiest methods for hanging paintings.
The Larks Head Knot (Cow Hitch)
Use this with picture hanging cord on lightweight picture frames. There are a few steps involved in this process. The first is to create a ‘loop’ with one part of the cord. The second part is to feed the loop through the D-ring or eyelet (depending on what hardware you are using), then feed the remaining cord through the loop, hitching it onto the hardware. Hence the nickname (cow hitch).
A Round Turn and Two Half Hitches
For heavier weight picture frames that can be supported by a strong enough hanging cord, a securer knot is called the ‘round turn and two half hitches’. The round turn is simply looping the cord through the D-ring or eyelet twice for one complete loop, then making two half knots to secure the cord to the hardware.
The first knot secures the cord and the second locks that knot in place. An added advantage with this type of knot is that it self-tightens under load, giving very little slack. Not enough for the knot to come slack.
Precautions: No hanging cord will last forever. It frays with time. If you are using cord with a heavy picture frame, be sure to check it periodically for any signs of fraying. The same thing happens with brass hanging wire. That too, can fray, weakening the strength of the wire over time.