Postage stamps reinvented how people communicate. Yet, as important as they are, few people know the process by which stamps are produced. There are lots of different stamp printing techniques out there, and it’s worth taking a closer look at each one.
9 stamp printing techniques are:
- Engraving
- Typography
- Photogravure
- Lithography
- Embossed (Relief) printing
- Holograms
- Foil Application
- Digital print methods
- Self-printing stamps
The printing process for stamps has evolved as printing technology has advanced. What was once exceptionally labor intensive is now a streamlined process that people with the right software and materials can do on their PC, laptop or smart device. Below, we discuss these techniques in more detail.
Why Stamp Printing Techniques Matter
It is not an overstatement to say that stamps changed the world and how everyday people communicate. Delivering letters and packages was once something that only the wealthy could afford. Once stamps hit the scene, however, just about anyone could send a letter or package without breaking the bank.
Before Stamps
Before stamps were introduced in England in 1840, the only folks who could afford to use postal services were those who could afford as much as a common worker’s daily pay to send a letter or package. Postage was paid on delivery and was a calculation of how many sheets of paper were in a package and the distance the package traveled to reach its destination.
Often, package senders would inscribe coded messages on the outer sheath of paper or the wrapping of a package. The person receiving the parcel would examine the parcel, see the coded message and refuse to accept the package. This allowed the delivery of correspondence while depriving the deliverer of payment.
A Major Impact
Stamps changed all of that. People still tried to cheat, but it was much harder. But suddenly, the sender was responsible for prepayment of delivery. But a stamp served as a receipt and because delivery expenses were spread across the entire postal service, just about everyone could afford to send a package.
This had a significant impact on people’s lives:
- Letters and packages that went great distances were now affordable
- Common people could correspond with friends and relatives
- The postal service in England was essentially codified as the official deliverer of correspondence
- The stage was set for the use of stamps worldwide
Once stamps took hold, the need to print them in large scale was created. The more popular the postal service became, the more there was a need for stamps and the more there was a need for printers of stamps. This has given rise to many different stamp printing techniques over the years.
9 Stamp Printing Techniques
1. Engraving
This printing method included Intaglio, line engraving and etching. While the process of engraving became more sophisticated over time, the basic formula is the same as when the process was invented.
Master Die
The first step was to create a master die. This involved taking a block of softened steel and imprinting the stamp design onto it. This step was initially done by hand, but when it is done today, the image is either photographed and an engraver copies it onto the steel block, or a computerized process etches the stamp onto the block.
When the etching of the block is complete, the block is allowed to cool and harden. The etching itself is reversed.
Transfer Roll
The next step is to transfer the engraving onto a transfer roll. This is the intermediate step that moves the image to the printing plate from the master die. The entire image is transferred from the master die onto a blank roll of soft steel by pressing the two together.
Once the image is transferred onto the steel roll, it is allowed to harden. The image left on the roll is in the correct orientation (the master die had the reversed image) and is called a relief or a relief transfer.
Plate
When the relief has hardened, it moves to the final step of the pre-printing phase. The transfer roll is positioned over a soft steel plate, pressure is applied, and the roll is rocked until the entire engraving has been transferred. Upon application to the plate, the design is reversed and recessed once again.
The transfer roll is applied as many images are on the sheet of postage stamps. When printed, the imagery on the plate is transferred to the postage stamp paper. The image on the sheet is the correct image as it appears on a postage stamp.
2. Typography
Typography includes letterpress, flexography, surface printing, high etch and dry offset. While typography was the official name for this type of printing throughout the first 100 years of stamp printing, it is now called letterpress. Typography is different from etching in that the imagery is raised and applied to postage stamp paper.
The master die for typography is very similar to engraved stamps, but unlike with engraving, there is an additional step. During this step, the design is transferred to another surface before it is applied to the transfer roll. The printing area on the final plate is raised.
3. Photogravure
This printing process involves a photographic image applied to a chemically sensitized metal plate. This is opposed to a photographic paper. The design is transferred photographically via a halftone or dot matrix screen. This process breaks the photographic reproduction into tiny dots.
Chemicals are applied to the plate and the dots for depressions. These are called cells. The depths and diameters of these cells depend on the shade of the design. Once all of the dots have appeared, ink is then applied to the plate and the surface is wiped clean.
The applied ink is deposited in the cells and then transferred onto paper when the paper is pressed against the plate. Photogravure is a technique that is usually used on multicolored postage stamps that use primary colors (red, yellow and blue) and black. It’s possible to produce just about any color using just these four, along with the dot matrix pattern.
The printing process uses four cylinders, with one for each color. When used today, these are computer-generated. Additionally, modern soft steel plates may be replaced with metal-coated plastic. This type of printing is also called Gravure, Rotogravure and Heliogravure.
4. Lithography
Lithography works because oil and water don’t mix. A design is first hand drawn or transferred from an engraving onto the surface of a lithographic stone, or onto a metal plate coated in an oily substance.
It is through this oily coatingthat the ink will later be transferred to the paper. It is held in place by an acidic fluid. This makes it repel the ink in areas that aren’t covered by the oily substance. Modern printing uses two methods of lithography.
Photolithography
This method uses photographic processes in the image design and transfers. Photolithography allows for more design options, including the use of screens, half-tones, sepias, etc. Each of these methods are combined with line work. Photolithography allows for large, solid areas to be printed. This is different from both photogravure and engraving.
Offset
Offset printing is a refinement of lithography that involves a rubber-covered cylinder. The cylinder takes the impression from a lithograph plate, which is then transferred to the printed surface. Offset printing is faster and so has replaced lithography in many instances, although the word lithography covers both photolithography and offset because the results are identical.
5. Embossed (Relief) Printing
Embossing involves imprinting the stamp’s image into the surface of a die. Leather or linoleum are usually used as the platen. The platen is what takes on the image of the die. When pressed together, the image is left in the form of relief, with some parts of the design protruding from the surface and other parts depressed into it.
This process is usually used for metallic inks and usually there is no color inside the image, but the outline of the image is inked. The image ink is often the same color as the printed surface.
6. Holograms
Hologram stamps have become popular since their introduction in Australia in 1988. Since that year, multiple countries have created and issued their own hologram stamps and that fact has increased public interest in collecting them.
More than 80 countries have issued hologram stamps, accounting for over 500 different types of stamp. The peak for hologram stamps was in 1999 and 2000, in celebration of the end of the century and the start of the new millennium.
At first, hologram stamps were a security measure against counterfeiting and reusing stamps. Since the mid 1990s, however, holograms were issued as much for their appeal as anything else.
Popular hologram topics have included:
- Planets
- Space exploration
- Animals
- Sports
- Sports figures
- Flags
This list is not comprehensive. There are many other hologram topics. Most hologram images are two-channel or animated.
Hologram Production Process
To create a hologram, a scale likeness must be created that is the precise size of the hologram when it is printed on the face of the stamp. The process to create the hologram image involves the image being recorded on photoresist material and chemicals corrode away exposed areas.
Photoresist is also known as “resist” and is a light-sensitive material used in photolithography and photoengraving. The result is a patterned coat on a specific surface. To start the process, a substrate is coated with a light sensitive organic material and a pattern is applied to block the light.
The result is that unmasked parts of the surface are exposed to light. A solvent is then applied to the surface and the light and developing solvent erode any regions that are exposed. This leaves behind a coating of whatever the mask pattern was, creating a mold. The mold is then used to press copies of an image much like with a phonograph.
Postage Stamp Holograms
A postage stamp hologram is a reproduction of those ridges on a plastic film, which is then applied to a reflective background. The background is usually made of silver or gold foil. The background reflects light through the film, making the pattern visible. The pattern makes the image appear three dimensional.
Common Usage
Hologram stamps are most often used in a specialty capacity. They are used to commemorate events, people, hobbies, and historical occasions.
7. Foil Application
In modern printing, color is often applied to postage stamps via an application of metallic foil that has been imprinted using a stamping die. The die is stamped on the foil, which can be flagged or textured. Color is then added to the pattern.
8. Digital Print Methods
Each year, the USA produces up to 40 billion stamps and can print more than 50 million each day. Typically, stamps are ready for distribution as soon as the printing process is complete. Modern printing methods have streamlined traditional stamp printing methods and have made the printing of stamps faster, less expensive, and made the stamps themselves harder to counterfeit.
Modern processes, however, have not meant that all traditional printing methods have been made completely obsolete. Many stamps today call for engraving work. The key difference is that the engraving is now done using computer software.
Scanners are used to copy the original artwork. Artists then modify the artwork to be more precise and to adhere to print production orders. The production orders provide stamp dimensions, color breaks, and any specialized instructions such as screens or foil application. Once the artwork is verified, the print run is authorized.
Printing Plates
Once a design is authorized, the digital design is transferred to printing plates, usually four in total. Each plate is assigned a color: Cyan, Yellow, Magenta and Black (CYMK). The same design is on each plate so entire sheets can be printed in one print run.
Once designed, each plate is loaded onto a printing press. The press blends and layers CYMK colors, according to the print production order. With stamps, additional ink is also added, which makes it harder to forge and helps inspectors perform quality control checks.
Timeline
Until 2005, the Bureau of Engraving and Printing did the majority of stamp print work. At that point, an effort was initiated to move stamp printing to the private sector. The process of securing a federal stamp contract is detailed and challenging. Only printers that can show the proper technique, skill, equipment and security can secure a federal contract.
Printers must also show that they fully comply with all federal employment, environmental and accounting methods. Because the process is so stringent, it is difficult break into the federal stamp printing business.
Perforating And Cutting
Once the stamps are printed, the rolls are reduced to the appropriate size, based on the stamp being printed. While the sheets are being cut, inspectors are looking for flaws in coloration, hue, perforations, image relay and paper quality. If a flaw is caught, the stamps with the flaw are pulled and, in most cases, destroyed.
9. Self-Printing Stamps
One of the most exciting developments for postal customers over the last 20 years has been the development of software for a PC, laptop or mobile device that allows a user to print stamps wherever they have a colored printer. Customers use software to print stamps in their homes or offices in the quantity they want as opposed to having to buy a set quantity.
Because of software and cost issues, the idea has not taken off the way it was envisioned, but it is becoming more popular, particularly among businesses. The product is not without its detractors, however.
Cost Of Print, Ink, And Supplies
Private printing of the stamps is one reason people criticize the process. The individual or the business using a postage-printing service must absorb the cost of the ink and supplies to have a valid form of postage. The cost of printing is higher as well because there are no volume discounts.
Rather than paying just the costof a stamp, people using this service are paying:
- Price of postage
- Usually a subscription to a postage-printing software support service
- Cost of printing the postage
That adds up to postage that costs more to print at home than if they were to go down to the post office to buy postage.
This is particularly true if you are business and send out a lot of mail or rarely send out mail at all. For the former, without a volume discount on printing, postage production costs can be high. For the latter, the subscription services most postage-print software provide are not worth the number of times the postage software is used.
Limited Value
When considered in total, the most tangible benefit of printing your own postage, whether you are a business or an individual, is saving a trip to the post office. For most people, again, from both scenarios, the convenience is not worth the cost.
So, who does benefit from this form of stamp production? That is a tricky question to answer. Because few individuals have a need for continuous stamp production, they are not the ideal customer. Businesses that send out a lot of mail will opt for meters, bulk purchases of stamps, or they’ll let a print and mail house handle their mail needs.
That really only leaves one group: Individuals or businesses that have a regular if not constant need for the convenience of avoiding the post office where the cost of self-printing is justified.
Self-Print Stamps Are Self-Adhesive Stamps
Postage you print on your own also uses self-adhesive stamps. Most philatelists do not like self-adhesive stamps for various reasons. At the least, self-adhesive and pressure sensitive stamps make it very difficult to remove a stamp from an envelope, which in turn can devalue a stamp and make collecting them tricky.
The impact on the overall value of the stamp collection is at the core of this objection, although the challenges in presenting a stamp on a partial cover is also a concern.
The Role Of Technology In Stamp Printing
Since they were invented, stamps have evolved as technology has advanced and various needs have arisen. Often, the needs pertained to customers trying to reuse stamps or counterfeit them. Sometimes, however, advancements were made because they helped the customer as well as enhancing the Post Office’s bottom line.
The first English Penny Black stamp, for example, was quickly ditched in favor of the English Penny Red. The reason was that it was easy to cover any cancellation marks on the black background, allowing reuse of the stamps. The Penny Red made covering the cancellation mark without being detected almost impossible.
Stamps have also gotten more sophisticated regarding features in stamps that make them exceedingly difficult to copy. Governments worldwide have used watermarks, color schemes, artwork, serial numbers and much more to keep people from producing their own stamps.
Printing Changes
Technology has made stamp printing much more dependable as well. Computerized production processes made printing stamps much easier and faster.
To start, artwork can be reviewed over the internet and quality assurance checks can happen online. This saves a lot of time in the process of printing proofs, reviewing the proof and getting a physical signoff to move forward with it.
Printers have also gotten faster, more accurate and more dependable. The process of making the artwork, through to the approval of proofs, and then to the actual print run has been streamlined significantly. The print run itself has improved because of technological improvements in speed.
Stamps themselves have been improved over time as well. These improvements include:
- More durable paper
- Anti-fraud features in the stamps themselves
- Better dyes and inks
- More precise perforations
Self-Adhesive Stamps
One of the greatest advances from a customer’s perspective is the invention, improvement, and use of self-adhesive stamps.
A self-adhesive stamp is a stamp that has a pressure sensitive adhesive or gum on one side. The benefit of the adhesive is that the stamps it is on do not require moisture to make them adhere to paper. Self-adhesive stamps are issued on full or partial sheets with a removable backing.
The first self-adhesive stamps were issued in tropical climates in the late 1960s to combat humidity activating water-based stamp gum. They were more broadly adopted because they allowed for unique and creative shapes to be die-cut.
In the USA, the first self-adhesive stamps were produced in 1974, but the adhesive discolored the stamp. The next self-adhesive version was cut in 1989, and by 2002 all new USA stamps were self-adhesives.
Stamp Collector Resistance
One group of people that has not always been thrilled with advancements in postal and stamp technology is stamp collectors themselves. This is because not every advancement has been collector friendly. For example, self-adhesive stamps have encountered a lot of criticism over the years for three reasons:
- The adhesive discolors the stamps
- Self-adhesive stamps are difficult to remove from a cover
- Those two factors diminish the value of a stamp collection
Discoloration
Over time, the discoloration issue has been addressed, although it is not foolproof by any means. Stamps will still discolor slightly if they are self-adhesive, but the discoloration is nothing compared to what it was 20 years ago.
Stamp Removal From Covers
Regarding removing self-adhesive stamps from envelopes, there have been slight improvements, but nothing significant. Self-adhesive stamps are still difficult to remove and the risk of damaging a stamp in the process is very real.
Impact On Value
That brings us to the third objection. If a stamp discolors over time, even slightly, the value of the stamp collection is diminished. If enough stamps discolor, the entire collection could lose most, if not all, of its value.
Additionally, if a stamp cannot be removed from an envelope, the method of collection must be altered. Traditional hinges or mounts will not work as well if at all. Having to accommodate the removal issue can lead to stamps being damaged and it presents odd logistical requirements for presenting a collection, given there is no effective way of storing the stamps.
Both realities influence value. The discoloration issue is obvious. Less obvious but no less important is the need to accommodate a stamp, plus its cover or partial cover. If a stamp collection cannot be presented in an attractive manner, its value is also negatively affected.
Rectification Efforts
Adding to this are the efforts of postal services to rectify the stamp removal issue. Using adhesive alternatives has in some cases resulted in stamps that are more difficult to remove from a cover. Traditional soaking in water does not work to remove self-adhesive stamps the way it works with traditional moisture activated gum.
What that means for the average collector is that the stamp remains on the cover, or the collector uses chemicals, like benzine or heptane solvents, to remove the stamps. This entails additional costs, skills and knowledge to do so in a way that preserves the stamp and does not pose any safety issues for the person using the chemicals.
This means that, while the average person may win out of improvements in the technology used in stamp production, collectors can lose out.
Final Thoughts
The printing of stamps has come a long way since stamps were first conceived in England in 1840. As printing technology continues to progress, stamp production 10 years from now will look very different to how it looks now. Understanding how stamps are made, though, is key to appreciating your stamp collection.