Just purchased some D Hooks so that I can hang my framed works and works on canvas a lot easier, the only disappointing thing was the cost for delivery which was almost as much as the hooks themselves (100 pcs), I was disappointed that there was no option for standard international delivery, the only option was first class. However looking at the prices and quantities of hooks from retail outlets, I found that I still had a better bang for my buck by purchasing them off ebay.
http://www.ebay.com.au/itm/100-MED-D-Ring-Picture-Hangers-100-SCREWS-triangle-/150770353159