First a preface: I am too young to ever have used 70 mm film. I bought my first medium format camera in 2001. I've all but given up on film. Right now I have no way to process it or print it. Still, once in a while I take a trip and take a lot of pictures, then pay out the nose to have it processed. What I can't understand is how 120 format survived while 70mm went a long time ago. Even more perplexing is how 220 has survived longer than 70mm. As far as I know there is no (or it's hard to get) perforated 70mm film, so unmodified Hasselblad backs are out of luck. Here's what I see, from my limited experience: 220 Film: This is a hardly satisfactory mutant hybrid of roll film and sheet film. Have to load it in the dark, like sheet film, but at least you get more exposures. I guess if you're willing to carry around a changing bag you can still use it. Otherwise, you better buy as many backs as you're going to take rolls for the day. I can't believe it still exists. 120 Film: Wasteful packaging---a "brick" comes wrapped in plastic, inside that ten little boxes, inside each a little bag, then the paper strip to unroll the film. Kodak and color films are marginally better in the single box with five baggies inside. You load the film, take 16 or less exposures, then you lick it like a stamp, and hope it holds. At least in Hasselblad backs the adhesive strip at the exposed end frequently gets caught in the back and ripped off. Thankfully, you can load it in the daytime. A minimal, but functional, selection of films is still available. 70mm Film: In the Hasselblad's case, make your back a bit longer (70mm vs. A12) and you have a huge number of exposures. Presumably can be loaded in daylight if it's already in a cartridge. Bulk loaders were available for the real fanatics. Hasselblad had a 500+exposure back that was enormous (and rare) and the typical 100-200 exposure back. I don't know how the pros do it, but I am certainly not changing film emulsions every 12 exposures on a single day while on a project. So if I had two or three fully-loaded standard 70mm magazines I'd be set. By the end of the day I bet not having to reload film would gain me an extra 30 minutes to an hour. Hell, I'd bet the back plate on the camera body would look nicer after 10 years, too. So how is it that 120 (and even less likely, 220) outlived 70mm? Any thoughts?