Up until 1840, all envelopes were handmade, each being individually cut to the appropriate shape out of an individual rectangular sheet. The direct mail industry makes extensive use of return envelopes as a response mechanism.
Some envelopes are designed to be reused as the return envelope, saving the expense of including a return envelope in the contents of the original envelope. Civil War those in the Confederate States Army occasionally used envelopes made from wallpaper, due to financial hardship.Ī "return envelope" is a pre-addressed, smaller envelope included as the contents of a larger envelope and can be used for courtesy reply mail, metered reply mail, or freepost (business reply mail). This was a legacy of the previous system of calculating postage, which partly depended on the number of sheets of paper used.ĭuring the U.S. If desired, a separate letter could be enclosed with postage remaining at one penny provided the combined weight did not exceed half an ounce (14 grams). The "envelope" used to launch the Penny Post component of the British postal reforms of 1840 by Sir Rowland Hill and the invention of the postage stamp, was a lozenge-shaped lettersheet known as a Mulready. Similar-looking envelopes with red and silver cords are used for weddings. The white and black cords represent death. Any handmade envelope is effectively a lettersheet because prior to the folding stage it offers the opportunity for writing a message on that area of the sheet that after folding becomes the inside of the face of the envelope.Ī Japanese funeral envelope used for offering condolence money.
Īn aerogram is related to a lettersheet, both being designed to have writing on the inside to minimize the weight. As of 2009 there is no international standard for window envelopes, but some countries, including Germany and the United Kingdom, have national standards. The treated area became sufficiently translucent for the address to be readable. One innovative process, invented in Europe about 1905, involved using hot oil to saturate the area of the envelope where the address would appear. In some cases, shortages of materials or the need to economize resulted in envelopes that had no film covering the window.
Callahan in 1901 and patented the following year. The window is normally covered with a transparent or translucent film to protect the letter inside, as was first designed by Americus F. They are generally arranged so that the receiving address printed on the letter is visible, saving duplication of the address on the envelope itself. Window envelopes have a hole cut in the front side that allows the paper within to be seen. They are most commonly used for enclosing and sending mail ( letters) through a prepaid-postage postal system. Although in principle the flaps can be held in place by securing the topmost flap at a single point (for example with a wax seal), generally they are pasted or gummed together at the overlaps. Patent drawing of Americus Callahan's windowed envelopeĪ folding sequence such that the last flap closed is on a short side is referred to in commercial envelope manufacture as a pocket – a format frequently employed in the packaging of small quantities of seeds.