Some corrections: Edison invented the 35mm standard that with a few small changes still lives on, not Kodak. 120 doesn’t refer to the width of the film, it’s

Some corrections: Edison invented the 35mm standard that with a few small changes still lives on, not Kodak. 120 doesn’t refer to the width of the film, it’s an arbitrary numbering Kodak invented along with a huge number of others that didn’t survive. It is 61mm wide in its current form. IMAX does have sprocket holes as it’s 65mm film but runs horizontally as you say for a larger frame size. Kodak loved non-standard film sizes because it meant they had a monopoly on producing it, to more and less success (look at disc film for one example).