120 and 220 are the two common sizes of modern medium format film and are used by all current medium format makers. The film is actually identical and all of the various formats, such as 6x4.5cm, 6x6cm, 6x7cm, 6x8cm, 6x9cm etc. can work with either. The difference between the two is that a 220 roll is twice as long as a 120 roll and gives twice as many exposures. 120 and 220 look identical from the outside as each has a paper backing. On 120 the paper backing extends the whole length of the roll whereas on 220 the paper is only at the beginning and end and is attached to the film with tape in the middle of the roll.

The film is not interchangeable; your camera will indicate which it takes. Some cameras can use either one and on others the the film back or insert must be swapped.

120 is the more common format and is more readily available at local stores but 220 is still very much alive.

I sell both types in my Ebay Store.

Feel free to write or call with more questions.