I decided to buy three obsolete envelope-making machines.

In 1845, Edwin Hill and Warren De La Rue were granted a British patent for the first envelope-making machine.

D. Wheeler Swift, a native of Falmouth, Massachusetts, was an inventor of envelope-making machines, and owned companies that used such machines.

Hill's brother Edwin Hill invented a prototype envelope-making machine that folded paper into envelopes quickly enough to match the pace of the growing demand for postage stamps.