Should I get a 36" or 42" wide bookcase?

A 36" bookcase holds roughly 12 standard 3-ring binders per shelf and is the most common commercial pick — at 42" you get 17% more storage per shelf, but unsupported shelf sag becomes a concern under heavy loads like law books or encyclopedias. For those heavy-load scenarios, the 36" width with center support is the safer bet. FindOfficeFurniture.com's 36" commercial bookcases are our top sellers — call 888-719-4960 to see current options.