Stamp Printing Methods: How to Tell Engraved, Lithographed, Photogravure and Typographed Stamps Apart

Two stamps can share a design, a color and a perforation and still be different catalog listings because they were printed by different methods. Printing method also matters for spotting forgeries: many fakes were made with a cheaper process than the original. The good news is that each method leaves physical clues you can learn to see with a 10x loupe and a raking light. This guide explains the main methods and what to look for.

Why printing method matters

For identification, the catalog for many countries lists the same design printed by different methods as separate issues. For authentication, a printing method that doesn't match what the catalog says is one of the clearest red flags for a forgery. Many historic forgeries were produced by lithography or by photographic processes imitating an engraved original. That doesn't make every lithographed stamp a fake, of course: many genuine stamps were lithographed. The point is to check that the method matches the issue. Our fake overprints guide covers related warning signs.

Tools and light

• A 10x loupe, or a USB microscope for photographing detail
• A light you can angle low across the stamp (raking light) to show relief
• A black background to see paper texture and embossing from the back
• A genuine reference example of the same issue, if you have one, or catalog illustrations

Browse USB digital microscopes on Amazon. Being able to photograph a line at high magnification and compare it side by side with a known example is often the fastest way to settle a question.

The methods one by one

Engraving (intaglio or recess printing)

In intaglio, the design is cut or etched into a metal plate. Ink fills the grooves, the surface is wiped clean, and paper is pressed into the grooves under high pressure. The ink sits on top of the paper as tiny ridges.

• Feel: on many engraved stamps, especially with heavy ink, you can feel ridges with a fingertip (gently, and only on stamps that can take handling) or see them under raking light.
• Lines: sharp, crisp and continuous, with tapered ends where the engraver's tool came out of the cut. Shading is built from lines and crosshatching, not dots.
• Back: sometimes a faint embossing or show-through of the design, from the paper being forced into the plate.
• Typical use: many classic and definitive issues worldwide, high-security designs, and portrait stamps.

Typography (letterpress or surface printing)

Here the design stands up from the plate surface, like a rubber stamp. Ink is applied to the raised parts and pressed onto paper.

• Edges: ink tends to be pushed toward the edges of lines and letters, so lines can show a slightly darker rim or a faint "squash" outline under magnification.
• Back: the pressure can leave a slight impression, the reverse of intaglio: the design is pressed in rather than raised.
• Surface: ink is flat, without the raised ridges of engraving.
• Typical use: many nineteenth- and early twentieth-century issues, and overprints and surcharges, which are very often typographed.

Lithography

Lithography prints from a flat surface treated so that ink adheres only to the image areas. There is no relief on the plate, so none on the stamp.

• Surface: completely flat ink, no ridges, no impression.
• Lines: can look slightly softer or less sharply defined than engraving, sometimes with a fine grain.
• Typical use: many genuine issues, especially from smaller printers or in periods of emergency; also many forgeries of engraved stamps.

Photogravure (rotogravure)

Photogravure uses a photographically prepared plate or cylinder etched with tiny cells of varying depth, broken up by a fine screen. Deeper cells hold more ink and print darker.

• Screen: under magnification, you see a fine regular pattern of cells or a grid, even in solid colors. This is the telltale feature.
• Edges: lettering and lines can look slightly jagged or stepped at high magnification because they're formed from cells.
• Tone: smooth gradations; well suited to pictorial designs and photographs.
• Caution: some watermark detection fluids can affect photogravure inks. Check the fluid's instructions before using it on these stamps.

Offset lithography

The most common modern commercial method. The image is transferred from a plate to a rubber blanket and then to paper. Tonal images are built from halftone dots.

• Dots: under magnification you see rosettes or rows of dots in different colors (often cyan, magenta, yellow and black, sometimes with extra spot colors).
• Surface: flat and even.
• Typical use: a large share of modern stamps, often combined with other methods.

Combinations and other methods

Many stamps combine methods, such as an engraved frame with a lithographed or gravure center, or offset backgrounds with engraved details. Embossing (raised design without ink, or with ink) appears on some classic issues and on postal stationery. Modern stamps may also use special techniques such as foils, varnishes and holograms. Catalogs usually state combinations, for example "engraved and lithographed."

Side-by-side identification table

These are general tendencies, not absolute rules. Wear on plates, ink consistency, paper type and printing pressure all change how a stamp looks.

A simple workflow

1. Look up what the catalog says about the issue. Note if more than one printing method exists for the design.
2. Check relief with raking light from the side. Raised ink strongly suggests intaglio.
3. Check the back on a black surface for embossing or impression.
4. Examine solid color areas and fine lines at 10x. Look for a screen (gravure), dots (offset), squeeze (typography) or crosshatching (engraving).
5. Compare against a known genuine example or reliable reference images at the same magnification.
6. If method doesn't match the catalog on a stamp that matters, stop and get an expert opinion. See expertizing certificates.

Practice material

The best way to learn is with common stamps where the method is known. Engraved definitives from many countries, typographed overprints, and modern gravure and offset issues are all plentiful. Mixtures and country lots are ideal for practice: browse engraved stamp lots on eBay and photogravure stamp lots.

When you're ready to research a specific issue where printing method separates two catalog listings, look at how sellers describe them and what actually sold: sold printing-variety listings on eBay. A secondhand specialized catalog for your area of interest is worth having too: specialized catalogs on eBay.

FAQ

The bottom line

For most collectors, three checks cover it: raking light for raised ink, the back for embossing or impression, and a 10x loupe on solid colors for screens or dots. Use them to confirm that a stamp's printing method matches what the catalog says. When it doesn't, and the stamp could matter, treat it as a question for an expert rather than a discovery.