By Fred Baumann
For a century and a half, forests have been leveled to provide the paper for philatelic publications to describe the various printing methods for stamps. This is crucial information.
Printing techniques can be used to tell the genuine from a forgery, to distinguish high-quality initial printings from subsequent inferior ones, and to determine which look-alike stamps were printed at different times, using similar but distinct technologies.
A collector who knows how a postage stamp was printed can tell a great deal about it.
The following descriptions are an abbreviated introduction to acquaint you with stamp printing. For completeness, it should be noted that machine-produced and computer-vended United States stamps use unconventional thermographic and electrically enabled printing techniques and media that are simply beyond the scope of this article.
At its most basic, stamp printing is the application of ink to one surface (the press) from which a design is transferred to paper (the stamp). This may be done directly, from press to paper, or by an indirect or offset printing process in which the ink is carried by a roller or some other intermediate means from the press to the paper.
There are four primary printing methods used to print most stamps. The first of these is intaglio, which includes line engraving and photogravure, although with the changing technology of the last half-century, these two are increasingly regarded as entirely independent printing technologies.
Intaglio is followed by planographic printing (which includes lithography and offset-lithography), relief printing (which includes letterpress and flexography), and embossing (the process used since 1853 for most U.S. stamped envelopes).
In appearance, the earliest presses to print postage stamps differed little from the first movable-type printing press that Johannes Gutenberg invented in Germany in the mid-1400s, or from the Spanish press that was the first in North America when it printed catechisms in Mexico City in 1539.
The first press to reach the U.S. colonies arrived a century later in Cambridge, Mass., and those used in the mid-1700s by men like Benjamin Franklin looked much the same.
Shown on page 25 is Gutenberg at his mid-15th-century press as pictured on a 1954 Germany commemorative (Scott 723) juxtaposed with a late 18th-century American colonial-era flatbed press pictured on the 1975 11¢ Americana definitive (Scott 1593).
Although these relief presses differ considerably from the line engraving used to print the first U.S. postage stamps, what these very similar presses on these two stamps represent is the slow evolution of printing technology.
Line-engraved plates on flatbed intaglio presses printed the first U.S. postage stamps in 1847, and all U.S. postage and revenue stamps for the next 70 years, up to the middle of World War I. One of the latter stamps of this period is shown on page 25, the 1¢ Balboa commemorative from the Panama-Pacific Exposition issue of 1913 (Scott 397).
In flatbed printing, flat printing plates are locked face up into a bed to form the printing surface.
In the earliest versions, leather-sheathed, wadded wool ink-balls pick up the sticky ink, which is beaten to thoroughly ink the printing surface. Slightly damp paper is then carefully laid over the inked plate. Paper, ink and plate are then positioned under the screw-operated press that gives the machine its name.
Using the leverage of that press, a wooden or metal platen compresses the paper slightly into the inked plate, which transfers to it a detailed impression of the inked design. Because the paper is forced into the press to pick up the ink, the dried ink is raised on the surface of the paper in the finished, dried print and has the distinctive, textured feel of printed currency.
Shown on page 25 is the eye of Herman Melville — an area about three millimeters square — as enlarged from the 1984 20¢ Literary Arts stamp (Scott 2094) engraved by veteran U.S. stamp engraver Thomas R. Hipschen, showing the skill, accuracy and deft touch needed to master line engraving.
Photogravure is broadly similar to line-engraved gravure printing, but achieves its effect through the efficiency and precision of photomechanical technology instead of the practiced skills and fine steel tools of a human engraver.
The desired design is photographed through a very fine screen to create a pattern of relatively shallow cells that can be etched onto the printing surface using an electrical or chemical process.
Because the cells that take the ink are so shallow compared to line engraving, and because pressure is not required to transfer the image as in line engraving, the resulting stamps feel smooth to the touch, but their distinctive dot structure readily seen under a magnifier identifies them as photogravure stamps.
A good example may be seen nearby in the various photogravure dot patterns enlarged from the 1984 20¢ Roberto Clemente commemorative (Scott 2097).
The opposite of engraving, in which designs are cut into the printing surface, is relief printing, in which the parts of the plate that receive the ink and transfer the image are elevated rather than inset. Consequently, the inked areas on the stamp are slightly sunken into the paper, rather than being raised above its surface, like the ribbon-inked letters that typewriters impress into paper.
Unlike relief or gravure printing, planographic printing uses a flat printing surface to apply ink to paper. This printing technique, which includes lithography and offset-lithography, instead relies on the well-known principle that oil and water do not mix.
In lithography, the printing surface is treated to hold water in areas that are not to do any printing, thereby repelling the greasy ink that is applied elsewhere to create the desired design. As a result, lithographed or offset-lithographed stamps have a flat appearance.
For 150 years of U.S. stamp printing, offset lithography was seldom used for U.S. postage stamps, but this is no longer true today. The vast majority of American issues since about 1990 have been printed by offset-lithography, sometimes in conjunction with line engraving.
Near the end of WWI, wartime shortages of men and material resulted in the use of offset-lithography to print the widely used 1¢ to 3¢ Washington definitives of 1918-20 (Scott 525-536). With images supplied courtesy of Robert A. Siegel Auction Galleries shown on page 28, exceptional mint examples of the engraved 1914 1¢ green (Scott 424) and the offset-lithographed 1¢ gray green (Scott 535) make the differences between the two easy to see.
Finally, embossing is the printing process by which U.S. stamped envelopes were made up to 1988. It involves the distortion of paper into the raised shape of all or part of a design by means of a low-relief metal die, a process that can be used with or without the addition of ink.
BUREAU OF ENGRAVING AND PRINTING
Although printing was well-understood, even early in the 20th century, production was becoming highly important. When the Bureau of Engraving and Printing introduced the rotary press in 1914, it became possible to print on continuous rolls of paper (called webs), as the printing plates were curved and attached to cylinders that rotate (hence, “rotary”) during printing.
Collector-stamp specialists have devoted considerable effort to the study of the various printing presses that produce American postage, beginning with that first rotary press.
BEP employee Benjamin F. Stickney designed the web-fed rotary press used at the Bureau from 1914 until 1962, appropriately referred to as the Stickney press. Shown on page 30, again courtesy of Siegel, is an example of the first stamp to come off that press, an imperforate 2¢ carmine Washington type I (Scott 459) produced for private perforation and sale by the U.S. Automatic Vending Machine Co.
With the advent of rotary presses, which greatly increased printing speed, flat printing plates that had been used previously were curved to fit the rotary press cylinders. However, in cases where the same issues were produced on both flat and rotary presses, the curving of the rotary plate resulted in a printed stamp in which the design was slightly longer in the direction in which the plate rotated.
In the early 1950s, the Stickneys were replaced by an experimental press produced by the Huck Co., which printed stamps at a much higher speed. This press was the short-lived prototype for the Cottrells that would bring a second increase in productivity just a few years later.
The first stamp produced by the Huck press was the 1952 3¢ International Red Cross (Scott 1016), an engraved commemorative in which the bright red cross was printed by letterpress, shown on page 30 — the first multicolored U.S. stamp of the post-World War II era.
As the 1950s progressed, the first Cottrell single-color intaglio rotary presses were delivered to the BEP. The 1956 3¢ Wheatland commemorative (Scott 1081) was the first stamp printed on these presses, which were in service for almost 30 years.
In 1957, the Giori press was introduced, requiring a single printing plate to print stamps with up to three different colors. This process allowed for the inking-in of each color on different parts of the same stamp during a single run through the press. The press made its debut with the 4¢ Flag stamp issued July 4 of that year (Scott 1094), shown on page 32.
In 1971, the Andreotti photogravure press was placed into service printing stamps. The 8¢ Missouri Sesquicentennial commemorative (Scott 1426) was the first U.S. photogravure stamp produced on this BEP press.
In 1973, the BEP obtained combination gravure and intaglio capability with its A press, followed by three-color intaglio B presses and C presses. By 1984, the D press — referred to as a combination press because it combined offset with intaglio printing — was introduced with the 20¢ Smokey Bear (Scott 2096), shown on page 32.
Recent decades have seen major changes in U.S. stamp printers, and in U.S. stamps.
The BEP, which began producing revenue stamps in 1866 and postage stamps in 1894, was the principal printer of U.S. stamps throughout the 20th century. Then, in the late 1980s through the 1990s, the U.S. Postal Service threw the door wide open to competitive stamp production, and a bewildering array of subcontractors, short-lived corporations and new names produced U.S. stamps.
The BEP left the field entirely after June 11, 2005, when it printed its final 37¢ Flag coils (Scott 3632) on an old four-color Andreotti press. Other versions of these same workhorse definitives were printed by no fewer than five private firms in 2002-05.
Thereafter, all U.S. stamp production was contracted out to private printing firms, a move that the U.S. Postal Service claims saves tens of millions of dollars each year. On U.S. issues of recent decades, however, understanding how stamps are produced has slowly come to eclipse the recognition of printing alone as the key to informed philately.
Today, three firms print U.S. stamps: Sennett Security Products; Ashton Potter USA Ltd.; and CCL Label Inc. (formerly Avery Dennison, which spun off its security printing business as part of a $500 million deal to Canadian-owned CCL Industries Inc., in 2013-14). These competitive private firms are not nearly as willing to share information on their security printing technology as the BEP once was, although some details are now known.
Sennett Security Products was founded by Richard Sennett, the former BEP assistant director who jumped ship in 1979 to become executive vice president at American Bank Note Co. (now Banknote Corp. of America, “a Sennett company” acquired in 2004).
It was under Sennett’s aegis that ABNC almost immediately broke the BEP monopoly to begin producing stamps for the USPS, beginning with the 1979 15¢ John Paul Jones commemoratives (Scott 1789-1789B) printed in multicolor photogravure on a Champlain press. The rare perf 12 variety of the stamp (1789B) is shown on page 34 courtesy of Siegel Auction Galleries.
Sennett’s self-proclaimed U.S. stamp production highlights include the 1990 25¢ Literary Arts commemorative honoring poet Marianne Moore (Scott 2449), the “first one to be produced entirely without film, in a new all-digital process.”
In 1995, SSP claims to have produced “the first 400-line gravure stamp.” SSP designed and manufactured the equipment used to produce the dramatic holographic Space souvenir sheets and stamps released at World Stamp Expo 2000 (Scott 3409-3413).
Ashton Potter USA Ltd. began printing postage stamps for Canada in five-color offset lithography in 1970 (Canada Scott 518). It expanded into the United States in 1990, and its first issue for the USPS was the 1993 Circus set of four (Scott 2750-2753).
Since then, AP expanded into printing U.S. postal cards in 2005 (Scott UX436-UX439) and stamped envelopes in 2008 (U663). Ownership of the firm has changed hands twice in recent years.
Before it became CCL Label, Avery Dennison’s entry into U.S. stamp production came by way of its experience as a top manufacturer of self-adhesive materials. This began with its ill-fated first outing in 1974 as the maker of the first such U.S. stamp, the notorious 10¢ Dove Weather Vane Christmas issue (Scott 1552). Pre-cut with a “+” and marked “PRECANCELED” to prevent reuse by recipients, used examples of this stamp separated into layers when soaked. Those who collected it mint fared no better, for the adhesive soaked through to the front, leaving unsightly brown blotches.
Chastened by that debacle, Avery International Corp. re-engineered its product and returned at the urging of the Postal Service in 1990 with the thin plastic 25¢ Flag stamp shown on page 36 (Scott 2475), produced in dollar-bill-sized 12-stamp panes to be vended by automatic teller machines. This was followed by a rapidly growing array of booklet and coil self-adhesives.
Fifteen years into the 21st century, how complicated has U.S. stamp printing become? Here’s a description from the March 4, 2008, issue of Graphic Arts Online of the 2007 nondenominated (41¢) forever Liberty Bell booklet (Scott 4126) printed by Avery Dennison:
“The stamps were gravure-printed in 10 colors on Fasson two-sided stamp stock with Siegwerk C Type solvent-based ink and using WRE Color Tech gravure engravings on a Dai-Nippon Kiko press. Printed using 300- to 400-line-screen engravings to make counterfeiting more difficult, the stamps include microprinting as the word ‘Forever’ is microprinted on each stamp.”
The ink-stained Colonial printer who first manned the Stephen Daye press in the mid-1600s might well suspect witchcraft was involved — and a significant number of U.S. collectors today would perhaps agree.
In the absence of much additional information, it is difficult to follow stamp production in 2015. Making it more complicated, stamp printing has been effectively replaced by stamp production, because the ability of the back of a U.S. stamp to peel and stick reliably has become as important to its commercial success as displaying an image and a value on its face.
Most U.S. stamps issued since 2002 have been self-adhesive, and the USPS announced in March 2015 that it would cease to issue any further moisture-activated stamps, citing the much higher cost of the paper they require.
Still, in 2015 as in 1840, with each new printing innovation comes a new area for those who love stamps to explore, learn about and collect.