For best viewing, the center of the framed image should be approximately 63” above the floor.
Any picture frame larger than 8” X 10” should be hung using two hooks. This reduces the torque on the frame and also prevents movement of the picture on the wall. If the wire on the frame is too tight to use two hooks then the frame should be re-wired.
When wiring a frame, the wire should be long enough so that the angle between the wire attaching point and the nearest hooking position is approximately 60° above horizontal. The wire should be short enough so that the hooks do not show above the top of the frame when hung. The attachment point should be about 1/3 of the distance down from the top. The wire should be attached to a good quality D-ring, not to an eye screw. The slight amount of torsion on the eye screw will, over time, cause the screw to become loose and pull out.
-- Always do the Right Thing the Right Way the First Time - if you can figure out what that is! Ken, Spring Branch, TX