Flat filing2, which emerged in the second half of the nineteenth century, was a more satisfactory interim storage technology [than pigeonholes] that increased efficiency of retrieval as well as capacity. The various types of flat files, in which document

Flat filing², which emerged in the second half of the nineteenth century, was a more satisfactory interim storage technology [than pigeonholes] that increased efficiency of retrieval as well as capacity. The various types of flat files, in which documents were stored flat rather than folded, eliminated abstracting, reduced retrieval problems, and allowed unlimited expansion. Forms of flat files ranged from bound volumes, simple imitations of the bound press book used for copies of outgoing correspondence, to rearrangable cabinet flat files, harbingers of the vertical filing systems that were to revolutionize storage and retrieval of documents.