The back of the saddlebags are made of a plastic like material, and that is the only truly hard part of the bags. The rest of the bags are made of an imitation leather (quite good) and the straps are of real leather, and the buckles allow a small padlock to keep them locked if you wish. The bags will keep their shape, its just that I was loading them with a tool roll the bottom would drop about an inch, so I used the wood to keep the bottom flat. I have read of others who said that the plastic back can crack if unsupported or loaded heavily, but that is not my experience. I have had them 3 years and they are as good as new.
