Is this a 12 pack of real 3 ring binders, or binder folders? These are twelve separate one inch three ring binders with round rings, not an accordion file folder or a pocket folder organizer. Are these 3 ring notebooks 1 inch, or an empty binder? The binder is empty and refillable, so it works as a 3 ring notebook once you add your own loose leaf paper, dividers and tabs. Is this a binder notebook with paper already inside? No. Nothing is bundled in the case, which is why the price per binder lands where it does. Add the paper you already buy. How many sheets does a one inch binder hold? Up to 225 sheets of 8.5 x 11 letter size paper, on back mounted round rings. What is the difference between round rings and D rings? Round rings sit on the spine and are easier to thread paper onto; D rings mount on the back cover and hold more per inch. Will this work for office organization and classroom organization? It handles the paper half of both. It stores pages, not pens or desk accessories. Is the cover printable? The clear view overlay takes any sheet you print yourself, on the front, the back and the spine, and you can change it as often as the project changes. Are these view binders with a clear view cover on the spine too? Yes. The clear view binder overlay wraps the front, the back and the spine, so a shelf of twelve can be labelled end on. Do the 3 ring binders 1 inch bulk packs work for a classroom set? Twelve matching blue binders is about one per student in a small group or one per subject for a department. Will sheet protectors, dividers and index tabs fit? Any standard 3 hole letter size insert fits the three rings, including sheet protectors, binder inserts and loose leaf refill paper. Are these round ring binders or D ring? Round. Round ring binders are the easier of the two to thread, and they keep the page block centred on the spine. What is in the box? Twelve binders and nothing else. No paper, no dividers, no tabs.