envelope

1. A flat paper container, especially for a letter, usually having a gummed flap.
2. Something that envelops; a wrapping.
3. Biology. An enclosing structure or cover, such as a membrane or the outer coat of a virus.
4. The bag containing the gas in a balloon or airship.
5. The set of limitations within which a technological system, especially an aircraft, can perform safely and effectively.
6. The coma of a comet.
7. Mathematics. A curve or surface that is tangent to every one of a family of curves or surfaces.

push the envelope

1. To increase the operating capabilities of a technological system.
2. To exceed the existing limits in a certain field; be innovative.

[French enveloppe, from envelopper, to envelop, from Old French envoloper. See envelop.]

USAGE NOTE   The word envelope was borrowed into English from French during the early 18th century, and the first syllable acquired the pronunciation (ŏn) as an approximation to the nasalized French pronunciation. Gradually the word has become anglicized further and is now most commonly pronounced (ĕnPRIMARY_STRESSvə-lōpSECONDARY_STRESS). The earlier pronunciation is still considered acceptable, however. A recent survey reveals that the (ŏnPRIMARY_STRESS-) pronunciation for the word envelope is used by 30 percent of the Usage Panel and is recognized as an acceptable variant by about 20 percent of those Panelists who normally use the (ĕnPRIMARY_STRESS-) pronunciation. Other similar words borrowed from French in the modern period include envoy (17th century), encore, ennui, ensemble, entree (18th century), entourage, and entrepreneur (19th century). Most retain their pseudo-French pronunciations, with the exception of envoy, which, like envelope, is mainly pronounced with (ĕn) now.

Background

An envelope is a flat, flexible container, made of paper or similar material, that has a single opening and a flap that can be sealed over the opening. The envelope is usually sealed by wetting an area of the flap. Some envelopes are sealed with a metal fastener. Others are sealed with a piece of string that wraps around flat, circular pieces of cardboard attached to the envelope. A recent development in envelopes is a thin strip of plastic, which is removed to reveal an area of the flap with an adhesive that does not need moistening.

Envelopes are almost always rectangular, but they exist in a wide range of sizes. The two main styles used are banker envelopes, which have the opening on the long side, and pocket envelopes, which have the opening on the short side. In the United States, standard sizes range from 3.5 x 6 in (89 × 152 mm) to 10 x 13 in (254 x 330 mm). In Europe, sizes range from 3.2 x 4.5 in (81 x 114 mm) to 11 x 15.75 in (280 x 400 mm). Sizes are somewhat different in the United Kingdom, with the most common being 4.25 x 8.625 in (108 x 219 mm).

Some envelopes have one or more windows cut into the front to allow addresses written on sheets inside to be seen. These windows may be covered with a transparent material.

History

The earliest ancestor of the envelope was used by the ancient Babylonians five or six thousand years ago. Messages were written on clay tablets, which were baked to harden them. The tablets were then covered with more clay and baked again. The inner tablet could only be revealed by breaking open the outer layer of clay, ensuring the security of the message.

True envelopes did not exist until much later, long after the invention of paper. The oldest form of paper was papyrus, first manufactured by the ancient Egyptians at least as early as 3000B.C. Papyrus was made from a fibrous material found within the woody stems of an aquatic, grassy plant (Cyperus papyrus). Long strips of this material were placed side by side, then covered with another layer of strips at right angles to the first. The sheet formed by the two layers was dampened, pressed, dried, flattened, then dried again. The resulting papyrus, if properly made, was pure white and free from spots and stains. An excellent writing material, papyrus was used extensively by the ancient Egyptians, Greeks, Romans, and Arabs. It continued to be used until paper made from other plant sources reached the rest of the world from China. Some papyrus was used in Europe as late as the twelfth century.

Early forms of Chinese paper, made from reeds and rice, date back as far as 1200B.C. A superior kind of paper, similar to modern paper, was first made about the year 105. Attributed to a court official named Ts'ai Lun, this improved paper was made from a mixture of materials, including mulberry and other woody fibers, hemp, rags, and fishing nets. Papermaking spread slowly from East to West, reaching Central Asia by 751 and Baghdad by 793. By the fourteenth century, there were several paper mills throughout Europe, particularly in Spain, Italy, France, and Germany. The development of the printing press in the 1450s greatly increased the demand for paper.

The early history of the paper envelope is not known. Paper may have been used to wrap messages at a very early date in China. They did not appear in Europe until the seventeenth century, when they began to be used in Spain and France. Until that time, messages were simply folded and sealed. Even today, some stationery is designed to be folded and mailed without an envelope.

Cotton and linen rags were the main raw materials used to make paper until the early nineteenth century, when they were replaced by wood. At about the same time, papermaking by hand began to be replaced by papermaking machines. The emerging envelope industry was noted by Karl Marx in his book Das Kapital in 1867. Envelope manufacturers continued to increase the speed of production, from three thousand envelopes per hour at the time of Marx to more than fifty thousand per hour in the late twentieth century. By the late 1990s, nearly two hundred billion envelopes were made in the United States each year.

Raw Materials

Most envelopes are made from paper. Some large, strong envelopes are made from synthetic materials, such as polyethylene. Polyethylene is a plastic made from ethylene, which is derived from petroleum.

Paper used for most envelopes is made from wood. Modern technology allows the wood to come from almost any kind of tree. Paper used to make very high quality envelopes, such as those used to enclose formal invitations, may be made partly or completely from cotton or linen. Some envelopes are made from manila, a fiber from the leaves of a plant found in the Philippines that produces a strong, yellowish paper. Most so-called manila envelopes, however, are made of paper derived from wood which only resembles true manila.

The glue applied to envelopes is of two basic types. The glue applied to the flap that is sealed by the consumer is usually a gum. A typical natural gum is gum arabic, derived from a substance produced by the acacia tree. Synthetic gums are often derived from dextrans, which are produced by the fermentation of sugar. The glue that holds the rest of the envelope must be stronger and more permanent. This glue is often derived from starches, which are obtained from corn, wheat, potatoes, rice, and other plants.

The fastener attached to some envelopes is made of aluminum or other metals. The string attached to other envelopes is made of cotton or other fibers. The material covering the windows in some envelopes is usually polystyrene. Polystyrene is a plastic made from styrene, a derivative of petroleum.

The Manufacturing
Process

Making wood pulp

• Mechanical methods can be used to transform wood into pulp, but this produces a relatively weak paper that is used for newspapers and similar products. Paper intended to be used for envelopes is made from pulp obtained by chemical means.
• The most common chemical method used to make wood into pulp is known as kraft pulping. Chips of wood are placed in a large, sealed container known as a digester. The digester contains a strongly alkaline solution of sodium hydroxide and sodium sulfide. The mixture is heated to a temperature between 320-356° F (160-180°C) at a pressure of about 116 pounds per square inch (800 kilopascals) for about one-half to two hours.
• Various methods exist to bleach the resulting pulp. Bleaching removes lignin, a substance found in wood pulp that gives paper a brown color. In general, bleaching involves mixing the pulp with a series of oxidizing chemicals that react with the lignin. After each mixture, the pulp is washed with an alkaline solution that removes the treated lignin.
• In order to improve the brightness, opacity, and smoothness of the paper, fillers are added to the pulp. A typical filler is a clay known as kaolin. Other chemicals often added to pulp include various starches or gums to make the paper stronger. Rosin (a substance derived from pine trees) and alum (aluminum sulfate) are often added as sizers. Sizing makes the paper less absorbent, so that addresses written on the envelope in ink will not run and blur.

Making paper

• Pulp is added to water to form a very dilute slurry in order to make paper with an even density. The slurry is pumped onto a moving mesh screen. This screen is made up of very fine wires of metal or plastic. Water drains through the small openings in the mesh, forming a sheet of wet material from the slurry. Rapidly spinning rollers beneath the mesh create suction, a partial vacuum that removes more water from the mixture.
• The sheet is moved on a belt made of felt containing wool and synthetic fibers. The felt absorbs water and prevents the sheet from being damaged as it moves between rollers, which squeeze out more water. The sheet then moves to a belt made of felt containing cotton and other fibers. This lighter felt allows water vapor to escape as the sheet is moved around a series of steam-heated rollers. As many as 40-70 rollers may be needed to dry the sheet.
• The dried sheet moves between rollers known as calendars to make it smooth. It is then wound on a large reel. Variations in the papermaking process produce paper in a wide variety of basis weights. The basis weight of paper is the weight, in pounds, of a ream of 480 sheets cut to a size of 24 x 36 in (610 x 914 mm). Envelope paper usually has a basis weight between 16 and 40, with a basis weight of 24 being typical. Although many other kinds of paper are coated after being made, envelope paper is usually uncoated.

Making envelopes

• Rolls of paper, typically weighing 220 lb (100 kg), arrive at the envelope factory. The paper may need to be cut before it enters the automated machine that makes the envelopes, or it may be fed directly into the machine from the roll. If it is cut outside the machine, it is first cut by sharp blades into sheets of the proper size. The sheets are then stacked into large piles for further cutting. Strong blades then cut the pile of sheets into blanks. A blank has the shape of an envelope with its flaps opened and laid flat. Blanks are generally shaped like diamonds and are cut from the sheets in such a way as to minimize waste. If the roll is fed directly into the machine, it cuts the paper into blanks very quickly with sharp blades.
• The machine performs all the operations needed to transform blanks into envelopes at a very rapid pace. Windows are cut if needed. If a transparent covering is needed for the windows, a strong glue is applied around them. The transparent material is then cut and glued in place. Strong glue is also applied to the places that will hold the envelope together. A weaker glue is applied to the flap that will be sealed by the consumer. The machine then folds the blank to form the envelope. Optional printing or fasteners are applied. The completed envelopes are filled in cardboard boxes and shipped to retailers.

Quality Control

Modern envelope manufacturing is highly automated, and almost always results in a reliable product. Although constant testing is not necessary, certain factors are checked to ensure quality. Paper arriving at the factory is inspected to be sure that it has the correct weight. A very small number of sample envelopes are checked to ensure that they have the correct shape and size, and that adhesives have been applied in the correct places. Any printing that appears on the envelope must be in the correct position, of the correct color, and without printing errors. If any windows are cut in the envelope, they must have the correct dimensions and be in the correct position.

The Future

Although major changes in envelope design are not expected, innovations are likely in the way paper is made. Manufacturers are constantly looking for ways to make paper that are more efficient, less costly, and result in less pollution. Genetic engineering may result in trees that grow faster and produce wood that is better adapted to producing pulp. A recent trend that is likely to continue is the increasing use of recycled paper as a raw material for making envelopes and other paper products.

Where to Learn More

Books

Biermann, Christopher J. Essentials of Pulping and Papermaking. New York: Academic Press, 1993.

Ferguson, Kelly, ed. New Trends and Developments in Papermaking. Miller Freeman, 1994.

Periodicals

Keman, Michael. "Pushing the Envelope." Smithsonian (October 1997): 30-31.

Other

Ohio Envelope Manufacturing Company. http://www.ohioenvelope.com/ (September 30, 1998).

[Article by: Rose Secrest]

(1) A range of frequencies for a particular operation.

(2) A group of bits or items that is packaged and treated as a single unit.

(3) See also pushing the envelope.

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A trading band composed of two moving averages, one of which is shifting upwards and the other shifting downwards.

Investopedia Says:
These trading bands are used by technical analysts to define a stock's upper and lower boundaries. Signals to sell occur when the stock price reaches the upper band, and buy signals are generated when the price reaches the lower band.

The reasoning behind the sell and buy signals is that stock prices tend to bounce off the bands. Even though buyers and sellers will temporarily pressure a stock's price to its extremes, it should re-stabilize to more realistic levels found within the envelope.

Related Links:
Discover one of the most reliable indicators in technical analysis and learn how to incorporate it into your trading routine. Moving Averages

Long before 1988, in the early years after World War II, push the envelope was on the cutting edge (1951) of aviation. It referred to the envelope, or limit of performance for an aircraft, and test pilots like Chuck Yeager who had "the right stuff" (in the phrase popularized by Tom Wolfe's best-selling 1979 book) were always on the edge of danger, pushing the envelope.

But it was only in about 1988 that we pushed the envelope of pushing the envelope beyond the fields of aviation and space so that it stretched to fit any enterprise. We began to speak of such matters as "pushing the envelope of taste," to take a 1991 example from the Wall Street Journal. Astronomers with the Hubble telescope, criminals with alibis, movie directors with scenes of violence or absurdity, con artists, and corporate raiders can now be said to be pushing the envelope in their various fields of endeavor.

We have many ways of saying it. Sometimes it is the edge of the envelope that we expand or stretch as well as push, whether in aircraft speed, computer power, campaign finance, or lifestyle. So in 1992, for example, Marilyn Quayle, wife of Vice President Dan Quayle, explained that she went rollerblading in neon tights because "I like anything that stretches the edge of the envelope a little bit."

envelope, a structural device in poetry, by which a line or stanza is repeated either identically or with little variation so as to enclose between its two appearances the rest (or part) of the poem: a stanza may begin and end with the same line, or a poem may begin and end with the same line or stanza. A well‐known example is Blake's poem ‘The Tiger’, in which the opening stanza is repeated as the last with only one change of wording. The effect of an envelope pattern is subtly different from that of a refrain. The term envelope stanza has also been applied to stanzas not involving repeated lines but having a symmetrical rhyme scheme (almost always abba) which encloses one set of rhymes within another, as in the In Memoriam stanza.

1. The imaginary shape of a building indicating its maximum volume; used to check the plan and setback (and similar restrictions) with respect to zoning regulations.
2. The folded-over, continuous edge formed by turning the lowest ply of a built-up roofing membrane over the top surface layer; prevents bitumen from dripping through the exposed edge joints and seepage of water into the insulation.

An encompassing structure or membrane. In virology, a bilayer lipoprotein membrane with glycoprotein spikes surrounding the nucleocapsid and usually furnished, at least partially, by the host cell. In bacteriology, the cell wall and the plasma membrane considered together.

• nuclear e. — the condensed double layer of lipids and proteins enclosing the cell nucleus and separating it from the cytoplasm; its two concentric membranes, inner and outer, are separated by a perinuclear space.

A poetic device in which a line, phrase, or stanza is repeated so as to enclose other material.

n.

The coffin of a document; the scabbard of a bill; the husk of a remittance; the bed-gown of a love-letter.

Tutor's tip: The postal "envelope" (a wrapper, a covering) was not big enough to "envelop" (to wrap up; to cover completely) the catalogs for mailing.

Envelopes usually signify anticipation or opportunity within a dream. If envelopes remain unopened, it may indicate that the dreamer has missed an opportunity. If the dreamer is eagerly anticipating an envelope's contents, it may mean that the dreamer will experience a wonderful outcome of an event in waking life.

This article is about envelopes in packaging. For other uses, see Envelope (disambiguation).

Front of an envelope mailed in the U.S. in 1906, with a postage stamp and address

Back of the above envelope, showing an additional receiving office postmark

An envelope is a packaging product, usually made of flat material such as paper or cardboard, and designed to contain a flat object, which in a postal-service context is usually a letter, card or bills. The traditional type is made from a sheet of paper cut to one of three shapes: the rhombus (also referred to as a lozenge or diamond), the short-arm cross, and the kite. These designs ensure that in the course of envelope manufacture when the sides of the sheet are folded about a delineated central rectangular area, a rectangular-faced, usually oblong, enclosure is formed with an arrangement of four flaps on the reverse side, which, by virtue of the shapes of sheet traditionally used, is inevitably symmetrical.

In 1876 William Irwin Martin published the Stationer's Handbook. He worked for the Samuel Raynor & Company in New York. He created the first commercial sizes of envelopes and simply numbered them from 0 through 12.

Contents 1 Overview 2 Post office requirements 2.1 International standard sizes 2.2 North American sizes 3 Manufacture 3.1 History of envelopes 3.2 Present and future state of envelopes 4 See also 5 References 6 External links

Overview

Envelope with advertising from 1905 used in the U.S.

Patent drawing of Americus Callahan's windowed envelope.

When the folding sequence is such that the last flap to be closed is on a short side it is referred to in commercial envelope manufacture as a '"pocket"' - a format frequently employed in the packaging of small quantities of seeds. 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. They are most commonly used for enclosing and sending mail (letters) through a prepaid-postage postal system.

Window envelopes have a hole cut in the front side that allows the paper within to be seen. They are generally arranged so that the sending address printed on the letter is visible, saving the sender from having to duplicate the address on the envelope itself. The window is normally covered with a transparent or translucent film to protect the letter inside, as was first designed by Americus F. Callahan in 1901 and patented the following year. In some cases, shortages of materials or the need to economize resulted in envelopes that had no film covering the window. One innovative process, invented in Europe about 1905, involved using hot oil to saturate the area of the envelope where the address would appear. The treated area became sufficiently translucent for the address to be readable. A typical use for window envelopes is courtesy reply mail.

An aerogram is related to a lettersheet, both being designed to have writing on the inside to minimize the weight. 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.

A Japanese funeral envelope used for offering condolence money. The white and black cords represent death. Similar-looking envelopes with red and silver cords are used for weddings.

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.^[1] If desired, a separate letter could be enclosed with postage remaining at one penny provided the combined weight did not exceed half an ounce (about 13 grams). This was a legacy of the previous system of calculating postage, which partly depended on the number of sheets of paper used.

During the U.S. Civil War those in the Confederate States Army occasionally used envelopes made from wallpaper, due to financial hardship.

A "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). 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. The direct mail industry makes extensive use of return envelopes as a response mechanism.

Up until 1840 all envelopes were handmade, each being individually cut to the appropriate shape out of an individual rectangular sheet. In that year George Wilson in the United Kingdom patented the method of tessellating (tiling) a number of envelope patterns across and down a large sheet, thereby reducing the overall amount of waste produced per envelope when they were cut out. In 1845 Edwin Hill and Warren de la Rue obtained a patent for a steam-driven machine that not only cut out the envelope shapes but creased and folded them as well. (Mechanised gumming had yet to be devised.) The convenience of the sheets ready cut to shape popularized the use of machine-made envelopes, and the economic significance of the factories that had produced handmade envelopes gradually diminished.

As envelopes are made of paper, they are intrinsically amenable to embellishment with additional graphics and text over and above the necessary postal markings. This is a feature that the direct mail industry has long taken advantage of—and more recently the Mail Art movement. Custom printed envelopes has also become an increasingly popular marketing method for small business.

Most of the over 400 billion envelopes of all sizes made worldwide are machine-made.

Post office requirements

Air mail envelope

A Chinese-style envelope used in Taiwan and printed for official use by the Legislative Yuan. The red box in the center is for the name of the recipient, written vertically in Chinese characters. The address is also written vertically to the right of the red box. The postal code is written in the boxes in the lower left-hand corner.

According to international postal conventions, a letter envelope must measure at least 90 × 140 mm. The length of postcards and aerograms must be at least the width times the square root of 2.^[2] These requirements help sorting letters by making it easier to line up all the envelopes with the addresses reading the same way.

The same regulations also reserve certain regions on the envelope for the address, the postage, as well as markings that can be added by sorting machines.

In some countries using postcodes, common envelopes are preprinted with lines and boxes that help write those postcodes in a consistent way in a consistent position.

In Australia, post office-preferred envelopes have four boxes printed in orange ink at the bottom right-hand corner where handwritten postcodes are meant to be written. Character recognition software is used to read the postcode number.

Envelopes in the Soviet Union were printed with something like the common 7 segment LCD, to assist the user to write the 6-character postcode directly in machine-readable format.

For First Class Mail in the United States, the Postal Service requires letter-sized envelopes to be between 5 inches and 11.5" wide, 3.5–6.125" high, and 0.007–0.25" thick.^[3] The large-envelope (or "flat") postal rate applies to envelopes 11.5–15" wide, 6.125–12" high, and 0.25–0.75" thick.^[4] Parcel rates apply to other envelope sizes.^[5]

While conforming to postal regulations can save postage and lead to a faster and more reliable delivery, postal workers usually try to deliver most non-standard-sized envelopes. ^[6]

International standard sizes

International standard ISO 269 defines several standard envelope sizes, which are designed for use with ISO 216 standard paper sizes:

Format	Dimensions (mm)	Suitable for content format
DL	110 × 220	1/3 A4
C7/C6	81 x 162	1/3 A5
C6	114 × 162	A6 (or A4 folded in half twice)
C6	114 × 229	1/3 A4
C5	162 × 229	A5 (or A4 folded in half once)
C4	229 × 324	A4
C3	324 × 458	A3
B6	125 × 176	C6
B5	176 × 250	C5
B4	250 × 353	C4
E3	280 × 400	B4

The German standard DIN 678 defines a similar list of envelope formats.

North American sizes

There are dozens of sizes of envelopes available. Not all are used for posting mail, but for such things as former pay packets or putting a gift card or a key in. U.S. and Canadian postal regulations^{[citation needed]} differ from those of the rest of the world; although envelopes are still deliverable worldwide by the regulations of the Universal Postal Union, the sorting machines will not accept the international sizes. This is not as much a difference as usually thought, for the location of sending address and return address differ between Germany and France, for example.^{[clarification needed]}

The designations such as "A2" do not correspond to ISO paper sizes.

Format	Dimensions (in)	Dimensions (mm)	Ratio
A2	4 3/8 × 5 3/4	111.1 × 146.1	132%
A6	4 3/4 × 6 1/2	120.7 × 165.1	137%
A7	5 1/4 × 7 1/4	133.4 × 184.2	138%
A8	5 1/2 × 8 1/8	139.7 × 206.4	148%
A9	5 3/4 × 8 3/4	146.1 × 222.3	152%
A10	6 × 9 1/2	152.4 × 241.3	158%
No. 6¾	3 5/8 × 6 1/2	92.1 × 165.1	179%
No. 7¾ (Monarch)	3 7/8 × 7 1/2	98.4 × 190.5	194%
No. 9	3 7/8 × 8 7/8	98.4 × 225.4	229%
No. 10	4 1/8 × 9 1/2	104.8 × 241.3	230%
No. 11	4 1/2 × 10 3/8	114.3 × 263.5	231%
No. 12	4 3/4 × 11	120.7 × 279.4	232%
No. 14	5 × 11 1/2	127.0 × 292.1	230%

Manufacture

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Nearly all of the estimated 450 billion envelopes made each year worldwide are machine-made.

History of envelopes

Prior to 1845, hand-made envelopes were all that were available for use, both commercial and domestic. In 1845, Edwin Hill and Warren De La Rue were granted a British patent for the first envelope-making machine.^[7]

The "envelopes" produced by the Hill/De La Rue machine were not as we know them today. They were flat diamond, lozenge (or rhombus)-shaped sheets or "blanks" which had been precut to shape before being fed to the machine for creasing and made ready for folding to form a rectangular enclosure. The edges of the overlapping flaps treated with a paste or adhesive and the method of securing the envelope or wrapper was a user choice. The symmetrical flap arrangement meant that it could be held together with a single wax seal at the apex of the topmost flap. (That the flaps of an envelope can be held together by applying a seal at a single point is a classic design feature of an envelope).

Nearly 50 years passed before a commercially successful machine for producing pre-gummed envelopes effectively as we know them today appeared.

The origin of the use of the diamond shape for envelopes is debated. However as an alternative to simply wrapping a sheet of paper around a folded letter or an invitation and sealing the edges, it is a tidy and ostensibly paper-efficient way of producing a rectangular-faced envelope. Where the claim to be paper-efficient fails is a consequence of paper manufacturers normally making paper available in rectangular sheets, because the largest size of envelope that can be realised by cutting out a diamond or any other shape which yields an envelope with symmetrical flaps is smaller than the largest that can be made from that sheet simply by folding.

The folded diamond-shaped sheet (or "blank") was in use at the beginning of the 19th century as a novelty wrapper for invitations and letters among the segment of the population that had the time to sit and cut them out and were affluent enough not to bother about the waste offcuts. Their use first became widespread in the UK when the British government took monoply control of postal services and tasked Rowland Hill with its introduction. The new service was launched in May 1840 with a postage-paid machine-printed illustrated (or pictorial) version of the wrapper and the much-celebrated first adhesive postage stamp: the Penny Black- for the production of which the Jacob Perkins printing process was used too deter counterfeiting and forgery. The wrappers were printed and sold as a sheet of 12, with cutting the purchaser's task. Known as Mulready stationery, because the illustration was created by the respected artist William Mulready, the envelopes were withdrawn when the illustration was ridiculed and lampooned. Nevertheless the public apparently saw the convenience of the wrappers being available ready-shaped, and it must have been obvious that with the stamp available totally plain versions of the wrapper could be produced and postage prepaid by purchasing a stamp and affixing it to the wrapper once folded and secured. In this way although the postage-prepaid printed pictorial version died ignominiously,the diamond-shaped wrapper acquired de facto official status and became readily available to the public notwithstanding the time taken to cut them out and the waste generated. With the issuing of the stamps and the operation and control of the service (which is a communications medium) in government hands the British model spread around the world and the diamond-shaped wrapper went with it.

Hill also installed his brother Edwin as The Controller of Stamps, and it was he with his partner Warren De La Rue who patented the machine for mass-producing the diamond-shaped sheets for conversion to envelopes in 1845. Today, envelope-making machine manufacture is a long- and well-established international industry, and blanks are produced with a short-arm-cross shape and a kite shape as well as diamond shape. (The short-arm-cross style is mostly encountered in "pocket" envelopes i.e. envelopes with the closing flap on a short side. The more common style, with the closing flap on a long side, are sometimes referred to was "standard" or "wallet" style for purposes of differentiation.)

The most famous paper-making machine was the Fourdrinier machine. The process involves taking processed pulp stock and converting it to a continuous web which is gathered as a reel. Subsequently the reel is guillotined edge to edge to create a large number of properly rectangular sheets because ever since the invention of Gutenberg's press paper has been closely associated with printing.

To this day all other mechanical printing and duplicating equipments devised in the meantime, including the typewriter (which was used up to the 1970s for addressing envelopes), have been primarily designed to process rectangular sheets. Hence the large sheets are in turn are guillotined down to the sizes of rectangular sheet commonly used in the commercial printing industry, and nowadays to the sizes commonly used as feed-stock in office-grade computer printers, copiers and duplicators (mainly ISO, A4 and US Letter).

Using any mechanical printing equipment to print on envelopes, which although rectangular, are in fact folded sheets with differing thicknesses across their surfaces, calls for skill and attention on the part of the operator. In commercial printing the task of printing on machine-made envelopes is referred to as "overprinting" and is usually confined to the front of the envelope. If printing is required on all four flaps as well as the front, the process is referred to as "printing on the flat". Eye-catching illustrated envelopes or pictorial envelopes, the origins of which as an artisitic genre can be attributed to the Mulready stationery - and which was printed in this way - are used extensively for direct mail. In this respect, direct mail envelopes have a shared history with propaganda envelopes (or"covers") as they are called by philatelists.

At the end of the 20th century a top of the range envelope-making machine cost in the region of $1 million and could produce 1200 pre-gummed envelopes per minute in boxes of 1000 ready for distribution. With manufacturing costs as high as this very few envelope-making machinery manufacturers appeared in the 19th and 20th centuries, and at the beginning of the 21st century the number satisfying the world demand remained low, with a single enterprise, Winkler+Dünnebier, producing two-thirds of the machines producing the 450 billion envelopes referred to above (which includes "pockets").

Consequently too the high cost of buying these high capital investment machines has to be factored into the operating costs of any enterprise which engages in producing printed envelopes, and so their line of business is the production of very large runs of the order of 50,000 and upwards. Depending on the size of the run this can entail the use of an entire web or reel. The result of this is that over the last 150 years or so the most common way of producing printed envelopes commercially has been to overprint on machine-made envelopes. Needless to say, only the largest of companies have a need for 50,000 or more envelopes at any one time. The drawback is that although printing on the face of an envelope is reasonably straight- forward, an envelope is not a flat sheet of paper and so if printing is required on one or more flaps this incurs higher cost as specialist printing skill is required. For small businesses with a need for relatively low volumes of printed envelopes, even if a case is made for a batch customised with no more than the company logo on the face, there is seldom justification for the added expense of printing on the flap side too. However the volume-related barrier to the use of customised envelopes by small businesses was subsequently lowered in the late-20th century with the advent of the digital printing revolution which saw the introduction of PC printers. Although designed primarily to process flat rectangular sheets these could be adjusted to also overprint on the face of rectangular machine-made envelopes in spite of the extra thickness - given suitable office applications software such as Microsoft's Word.^{[citation needed]}

Present and future state of envelopes

Then right at the end of the 20th century, in 1998, the digital printing revolution delivered another benefit for small businesses when the U.S. Postal Service became the first postal authority to approve the introduction of a system of applying to an envelope in the printer bin of a PC sheet printer a digital frank or stamp delivered via the Internet. With this innovative alternative to an adhesive-backed postage stamp as the basis for an Electronic Stamp Distribution (ESD) service, a business envelope could be produced in-house, addressed and customised with advertising information on the face, and ready to be mailed.

The fortunes of the commercial envelope manufacturing industry and the postal service go hand in hand, and both link to the printing industry and the mechanized envelope processing industry producing equipments such as franking and addressing machines. They are all four symbiotic: technological developments affecting one obviously ricochet through the others : addressing machines print addresses, postage stamps are a print product, franking machines imprint a frank on an envelope. If fewer envelopes are required; fewer stamps are required; fewer franking machines are required and fewer addressing machines are required.^{[citation needed]} For example, the advent and adoption of information-based indicia (IBI) (commonly referred to as digitally-encoded electronic stamps or digital indicia) by the US Postal Service in 1998 caused widespread consternation in the franking machine industry,as their equipments were effectively rendered obsolescent and resulted in a flurry of lawsuits involving Pitney Bowes among others. The advent of e-mail in the late 1990s appeared to offer a substantial threat to the postal service. By 2008 letter-post service operators were reporting significantly smaller volumes of letter-post, specifically stamped envelopes, which they attributed mainly to replacement by e-mail. Although a corresponding reduction in the volume of envelopes required would have been expected, no such decrease was reported as widely as the reduction in letter-post volumes.

Although as regards e-mail developments there is a substantial threat of "technology replacing tradition", this is offset by the equal reasoning that the Universal Postal Union is an international specialised agency of the United Nations, and a source of revenue for government. Consequently any deterioration of domestic and international postal services attended by loss of revenue is a matter of governmental concern.

See also

• Secrecy of correspondence
• Return address
• Back-of-the-envelope calculation
• Packaging
• Paper size
• Mail Art

References

1. ^ "Mulready stationery: Lettersheets and envelopes". The Queen's Own: Stamps That Changed the World. National Postal Museum. http://www.postalmuseum.si.edu/queen's/mulreadystationery-list2.html. Retrieved 2006-09-25. 
2. ^ Universal Postal Convention, Article 12, RL122. In: Universal Postal Union – Letter Post Manual, page D.4
3. ^ "USPS - Mail Characteristics - Sizes for Letters". United States Postal Service. http://pe.usps.com/businessmail101/mailcharacteristics/letters.htm. Retrieved 2009-03-20. 
4. ^ "USPS - Mail Characteristics - Sizes for Large Envelopes and Flats (Nonletters)". United States Postal Service. http://pe.usps.com/businessmail101/mailcharacteristics/flats.htm. Retrieved 2009-03-20. 
5. ^ "USPS - Mail Characteristics - Sizes for Parcels". United States Postal Service. http://pe.usps.com/businessmail101/mailcharacteristics/parcels.htm. Retrieved 2009-03-20. 
6. ^ http://www.iuoma.org/extrememail.html
7. ^ http://www.makingthemodernworld.org.uk/stories/the_age_of_the_engineer/03.ST.03/?scene=7&tv=true

External links

Look up envelope in Wiktionary, the free dictionary.

Wikimedia Commons has media related to: Envelopes

• International standard paper sizes: ISO 216 details and rationale
• ISO 216 at iso.org
• The Stationers Handbook
• Envelope Sizes
• American envelope sizes
• European envelope sizes and their uses
• Print Envelopes online - free Application
• My Design Primer - standard envelope sizes
• Envelope sizes and flap configurations
• John Johnson Collection Exhibition 2001
• First Day of Issue, 6 May 1840, Mulready letter sheet Royal Insight (British Monarchy website)
• Mulready's, Parodies, Lampoons & Caricatures
• Propaganda Envelopes, Hand-Painted Envelopes, Reproductions and Forgeries
• Proof of One Penny Mulready lettersheet British Postal Museum and Archive
• Proof of Two Penny Mulready envelope British Postal Museum and Archive

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - konvolut, hylster, ballonhylster, kolbe, pære, enveloppe, svøb, indhyldningsflade

Nederlands (Dutch)
envelop, wikkel, verpakking, schil, curve, beperking, (gas)ballon, omkleding, omsingelen

Français (French)
n. - enveloppe, pli

Deutsch (German)
n. - Hülle, Briefumschlag

Ελληνική (Greek)
n. - φάκελος, περίβλημα, χιτώνας

Italiano (Italian)
involucro, busta

Português (Portuguese)
n. - envelope (m), tegumento (m) (Biol.), halo (m) (Astron.)

Русский (Russian)
конверт, оболочка, пленка, конверт с маркой и написанным адресом

Español (Spanish)
n. - envoltura, revestimiento, sobre

Svenska (Swedish)
n. - kuvert, omslag

中文（简体）(Chinese (Simplified))
信封, 封袋, 封套

中文（繁體）(Chinese (Traditional))
n. - 信封, 封袋, 封套

한국어 (Korean)
n. - 봉투

日本語 (Japanese)
n. - 封筒, 包み, 覆い, 包絡線, 範囲, 外皮

idioms:

• stamped addressed envelope    返信用封筒

العربيه (Arabic)
‏(الاسم) ظرف, غلاف‏

עברית (Hebrew)
n. - ‮מעטפה‬

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