1902, Americus F Callahan, Granted the Patent for Window Envelope
On this day on June 10, 1902, Americus F. Callahan of Chicago, Illinois, in the United States, granted the first patent for Window Envelope.
The United States patent number for Callahan’s design is 701,839. However, the Window Envelope originally called an “Outlook Envelop”. The patent initially anticipate using the thin rice paper as the transparent material forming the window, though this material has since been replace by clear plastics.
The design has otherwise remained nearly unchanged. On December 9, 1901, Callahan applied his Windowed Envelope invention for the patent.
Therefore, the Outlook Envelop reduce the need to print the addresses onto the envelope itself. As a result, the time of Callahan’s invention done with the aid of the typewriter. Callahan specifically recommended the use of Manila paper, which is considerably cheaper than thicker writing paper.
A windowed envelope is a conventional envelope with a plastic window to allow the recipient’s address to be print on the paper contain within.
However, the window needs to be cut out and from time to time it needs to replaced by an additional material called a patch. As a result, this makes the envelope more expensive. Further, there was an argument that the paper of the envelope can be substitute with lesser-quality paper as the envelope. Meanwhile, the quality of paper generally has improved more.
As a result of World War II, in 1940, Britain made an envelopes by newspaper, because of the paper shortage.
Importantly, owing to the benefits in both times, cost, and quality. Meantime, the windowed envelope design has become nearly popular among modern commercial mailings. However, recycling after use, plastic windows are not usually an issue for paper mills as the window can normally be easily screened out during the manufacturing process.