How Did We Get 8 1/2 by 11 Inches Paper?

From the June 2017 Smithsonian Magazine.

Question:  "How did we get 8 1/2 by 11 inches as the standard size for letter paper?"  James Cloonan, Rochesterm New York.

Answer by Helena E. Wright, curator of the division of culture at the National Museum of American History:

Early paper sizes were limited to what a vatman -- the worker who dipped a paper mold into a vat of pulp -- could handle.  Sizes varied within certain ranges.

In the late 1600s, papermakers invented molds that produced sheets that could be quartered into leaves of about 8 1/2 and 11, and businesses gradually adopted variations on that size.  By the 1920s -- despite efforts of a government-appointed Committee for the Simplification of Paper Sizes --  most private firms were doing business on 8 1/2 by 11, and federal employees on 8 by 10 1/2.

That disparity persisted until 1980, when the government adopted 8 1/2 by 11 as its standard as well.

Paper Me.  --Cootpaper