Although many collectors are snooty to library editions, a few of us tend to like gazing at the blue, yellow, red, and green spines better than a yellowspine jacket in mylar. . Although Grosset & Dunlap had an official library binding, many binderies did up special Hardy Boys editions for libraries all over the States & Canada. 'Research' in this field is far from complete, and probably never will be, but I (with the invaluable help of Paul Mular) have listed as many binders/formats as I can. . APC  |  Houshen  |  Bound-To-Stay-Bound  |  PermaBound  |  FLB  |  TT  |  Multipic | Miscellaneous