In the 50s, 60s, and 70s shops that sold film often kept it in diamond shaped shelves behind the check out counter. Those shelves were a distinctive graphic on the wall that said "film sold here" whether you were in a photo shop, a national park gift shop, drug store, or grocery store. My question is, were those shelves sold/provided by Kodak? Was there any reason - relating to storage, inventory counting etc. - for the shape?