Make a loop as described.
Open the leaves of the came at the top and solder the wire with the loop to the heart of the came. Use as little solder as possible and keep it away from the leaves, as solder on the leaves makes folding the leaves back very difficult.
Continue the wire around the side. Pull the wire tight and tack solder the wire at the bottom of the side. Continue the wire around the bottom and do the same at the other side.
Pull the wire tight to the top of the panel. Bend the wire over at the height you wish the loop to appear above the panel. Twist or bend the wire and solder it to the side of the came’s heart.
Close the flanges of the came over the wire and you have a neat finish to the edges.
You can, of course, decide to hang the panel from the wire going around the panel. In this case you eliminate the loop forming at each side of the panel’s top. I solder the wire ends together at the bottom, in addition to soldering the wire to the came at each corner. This provides me with the certainty that the wire will not come loose.
This can also be used to provide the hanging supports when placing the panel in a wooden frame. It takes the strain off the frame but still provides firm support of the panel.