How Banknotes Are Printed: Intaglio, Offset and Letterpress
A banknote is built in up to four separate printing passes, not one: offset lithography for the background colour, intaglio for the raised portrait and lettering, letterpress for the serial numbers and seals, and screen printing for thick colour-shifting inks. The scale is industrial. The United States alone ordered 3.8 billion to 5.1 billion notes for calendar year 2026, worth $108.9 billion to $139.6 billion (Federal Reserve Board, 2026 Currency Print Order).
Last updated: July 2026
A modern banknote is printed in layers by up to four different processes: offset lithography lays the flat background colour, intaglio presses ink into the sheet under enough pressure to leave a raised relief you can feel with a fingertip, letterpress overprints the serial numbers and seals, and screen printing applies ink films thick enough to carry optically variable pigment, all onto a substrate of either cotton-linen rag paper or polymer film. A magazine page uses one process. A currency note uses several, deliberately, because the combination is expensive to assemble and each layer leaves evidence the others cannot fake. Knowing the sequence is the fastest route to reading a note the way an authenticator does, since almost every hands-on test a collector performs is really a test of one printing stage.
Why does one banknote need four different printing processes?
Because each one does something the others physically cannot. Offset prints fine multi-colour backgrounds fast and cheaply but lies perfectly flat. Intaglio builds a relief you can feel, but it is slow. Letterpress can change its image on every impression, the only way to give each note a unique serial. Screen printing alone lays ink thick enough to hold the microscopic flakes that make a numeral shift colour. Stack all four and you get an object that is cheap to make in the billions and expensive for anyone else to imitate convincingly.
The logic is layered defence rather than one unbreakable trick. A good scanner and a fine inkjet can approximate the offset layer without much trouble. Reproducing the intaglio ridge needs a press capable of very high pressure and an engraved plate that took an artist months. Matching screened optically variable ink needs a pigment supply chain that sells only to authorised security printers. Every layer is another problem a forger has to solve independently.
This is why hands-on authentication works. Run a fingertip across a portrait and you are testing the intaglio pass. Tilt the note under a lamp and you are testing the screen pass. Our reference on banknote security features covers what each layer looks like on a genuine example; this page covers how they got there.
| Process | How it works | What it puts on the note | How you recognise it |
|---|---|---|---|
| Intaglio | Image is engraved into a steel plate. Ink fills the recesses, the surface is wiped, and the sheet is forced into the grooves under very high pressure. | Portrait, vignettes, main lettering, denomination numerals, latent images, tactile marks for the visually impaired | Raised ridges you can feel with a fingernail; crisp line endings under magnification; ink standing above the paper at a low angle |
| Offset lithography | Flat plate using oil and water repulsion. Ink goes plate to rubber blanket to sheet, which is what "offset" means. | Background tints, guilloche rosettes, rainbow colour blends, halves of a see-through register, fine anti-copy patterns | Perfectly smooth to the touch; continuous soft colour transitions; front and back elements that align when held to a light |
| Letterpress | Raised type strikes the sheet directly. Numbering boxes advance mechanically with every impression. | Serial numbers, prefixes and suffixes, seals, overprints, series dates, signature blocks on some issues | Slight bite or indentation on the reverse under raking light; ink often a different colour and gloss from the main design |
| Screen printing | Ink is pushed through a fine mesh stencil, depositing a far thicker film than any other press. | Optically variable colour-shifting ink, iridescent stripes, dynamic rolling-bar effects, some phosphorescent and infrared inks | Colour changes as you tilt the note; the printed area has perceptible body and gloss compared with its surroundings |
Why does intaglio produce the raised feel authenticators check first?
Intaglio leaves raised ink because the image is cut into the plate rather than raised on it. Engraved lines are packed with a stiff, high-pigment ink, the plate surface is wiped clean, and the sheet is driven into those recesses under enormous pressure. The ink lifts out of the grooves and stands on the sheet as a measurable ridge. That ridge is the most durable authentication cue on a banknote, because a scanner reads only colour and an inkjet can only lay ink flat.
The difference between old and modern intaglio matters. Fine-art intaglio and the earliest banknote engraving dampened the paper first so it would stretch into the lines. Modern security printing does not. The Bureau of Engraving and Printing adopted a dry intaglio process on specially made paper, where press pressure alone forces the sheet into the engraving. That change also allowed larger sheets. The Bureau moved to eighteen notes per plate in 1952, and the dry intaglio method introduced in 1957 took the sheet to thirty-two notes. Since 1968 all United States currency has been printed by the dry intaglio process (Bureau of Engraving and Printing production history).
The plates are the slow part. Lines are cut with a hand-held burin, which is engraving, or bitten with acid, which is etching. A master engraver's portrait die can take months, and the line work has properties no photographic process reproduces: lines that taper and terminate cleanly, cross-hatching that stays open at magnification, lathe patterns generated mathematically rather than drawn. Intaglio also enables the latent image, a word or numeral visible only at a shallow angle because its lines run in two directions.
The practical upshot for collectors is simple: feel the note before you look at it. A genuine intaglio note has texture on the portrait, the numerals and usually the border lettering. If an issue that should carry engraving is uniformly smooth, that is the first thing to investigate, and how to spot a counterfeit banknote covers what to check next. Pressure and ink film also degrade across a run, so a note struck early from a fresh plate simply looks better, which our banknote grading guide explains under eye appeal.
What does offset lithography contribute to a banknote?
Offset supplies everything flat, coloured and finely patterned: the tinted underprint, the guilloche lacework, the rainbow blends, the anti-copy moiré patterns and the two halves of a see-through register. It is indirect printing. The image is inked onto a flat plate that holds ink in the image areas and water everywhere else, transferred to a rubber blanket, and only then rolled onto the sheet. That blanket is what "offset" describes, and it is why the process renders fine detail on textured rag paper so cleanly.
The security value comes less from the process than from the press configuration. Security presses print both sides of the sheet in the same pass, so front and back are laid down against each other rather than in two separate runs. Registration is therefore held to a tolerance ordinary commercial printing never needs. That is what makes the see-through register possible: an incomplete shape on the front and another on the back that combine into one perfect symbol against a light. Reproduce that in two passes through a desktop printer and the halves will not line up.
Offset also carries rainbow or iris printing, where inks blend gradually across the sheet with no visible boundary between colours. A photocopier tends to band those gradients rather than reproduce them. Many terms collectors meet in auction descriptions, from guilloche to underprint to register, describe this layer, and our banknote glossary defines them individually.
Why are serial numbers and seals printed last, by letterpress?
Serial numbers go on last because they are the only elements that change from note to note. Letterpress uses raised type, the oldest of the four principles, and its numbering boxes advance mechanically with each impression, so every sheet leaves the press carrying numbers no other sheet has. Everything printed earlier is identical across the run. Reversing the order would mean re-registering a numbered sheet through a high-pressure intaglio press, risking damage to notes already individually accounted for.
Letterpress also applies seals, treasury or central bank marks, series dates and, on many issues, signature blocks. Because the type is raised and struck directly, it often leaves a faint indentation visible on the reverse under raking light, and the ink usually differs in colour and gloss from the layers around it. On United States Federal Reserve Notes the serial numbers and seal have historically been overprinted in a distinct colour.
Numbering is where accountability enters production. Sheets are counted and reconciled, and a sheet damaged during inspection cannot be reprinted with the same numbers without breaking the count. Issuing authorities substitute a specially marked replacement instead, which is why star notes and replacement notes exist and why they are scarcer than regular issues from the same run.
The same stage explains an entire collecting category. Specimen notes are genuine printings distributed to central banks and note-issuing correspondents for reference, distinguished precisely by what happened at the letterpress stage: zeroed or repeated serial numbers, a SPECIMEN or MUESTRA overprint, sometimes a punch cancellation. Real design, real substrate, real plates. Only the last pass differs.
Screen printing is how colour-shifting ink gets onto a note
Screen printing pushes ink through a fine mesh stencil, and it is the only process here that deposits a film thick enough to hold the microscopic interference flakes that produce optically variable ink. Those flakes are multi-layer structures that reflect different wavelengths depending on viewing angle, and they need physical depth in the ink layer to orient themselves. A numeral that shifts from green to copper as you tilt it is screened, not offset. The pass runs late, usually after intaglio, and only over small targeted areas.
The same process handles several other effects. Iridescent stripes that flash a colour across a plain field are screened. Dynamic elements showing a bright bar rolling across a shape combine screened ink with a fine embossed or lens structure. Phosphorescent and infrared inks, invisible under normal light and readable only under a specific lamp or sensor, are screened for the same reason: the effect depends on ink depth, not ink colour.
For a collector this is the fastest single visual test on a modern high denomination, and the layer where novelty replicas most often give themselves away. A printed imitation of a colour-shifting numeral is a two-tone graphic that stays two-tone at every angle. Genuine optically variable ink transitions continuously, and the patch has a soft body under a fingertip quite unlike the sharp ridge of intaglio.
What is a banknote actually printed on?
Most banknotes are printed on rag paper made from cotton, frequently blended with linen or other textile fibres, and a growing minority on polymer film. United States currency paper is 75 percent cotton and 25 percent linen (Bureau of Engraving and Printing), with no wood pulp at all, which is why a note survives a wash cycle that would reduce ordinary paper to fibre. A United States note measures about 156 mm by 66.3 mm and roughly 0.11 mm thick (Bureau of Engraving and Printing).
The substrate is not a passive carrier. Rag paper is where the watermark and the security thread are created, and both happen during paper forming rather than printing. A true watermark is a variation in fibre density built into the wet sheet, which is why it reads from both sides and cannot be added afterwards. The American mill Crane, founded in Dalton, Massachusetts in 1801, developed a method of embedding parallel silk threads into banknote paper as early as 1844 and won a contract to supply the Bureau of Engraving and Printing in 1879 (Crane Currency company history).
Polymer changed the equation. Australia produced the first modern polymer banknote in 1988, a ten dollar bicentennial commemorative developed with the Reserve Bank of Australia, CSIRO and the University of Melbourne, and by 1996 had converted every denomination (Reserve Bank of Australia and CSIRO). New Zealand converted its full series in 1999. Romania issued its first polymer note that same year, a two thousand lei commemorative for the total solar eclipse of 11 August 1999, and converted its full series to polymer in 2003. Canada converted between 2011 and 2013, and the Bank of England issued its first polymer five pound note in September 2016, completing the transition in June 2021 (Reserve Bank of New Zealand, Banca Nationala a Romaniei, Bank of Canada and Bank of England). Polymer still takes offset and intaglio on coated areas, but with no fibre structure it cannot hold a watermark or embedded thread, so the film carries a transparent window and integrated holographic elements instead.
Substrate is also where crisis printing shows itself most vividly. German emergency issues of the early 1920s were produced by local authorities on whatever was to hand, including linen, leather, silk and wood, a category covered on our notgeld emergency money page. State printing tells the same story in the number of passes it skipped. At the peak of the crisis the Reichsdruckerei was running with some 60 private firms drafted as auxiliary printers (Bundesdruckerei), and many late 1923 Reichsbank issues went out with no reverse printing at all. The first version of the 100 trillion mark note, dated 26 October 1923, is a plain one-sided design, while the definitive note, dated 15 February 1924, is a multicolor lithograph from the Reichsdruckerei (geldscheine-online and Muenzkabinett, Staatliche Museen zu Berlin). Dropping a pass is a production decision made under pressure, still legible on the object a century later.
| Substrate | Composition | Features built into the material | How it takes printing |
|---|---|---|---|
| Cotton-linen rag paper | Cotton fibre, often blended with linen, abaca or other textile fibres. United States currency is 75% cotton and 25% linen (Bureau of Engraving and Printing). | True watermark, embedded security thread, coloured or fluorescent fibres, planchettes | Takes deep intaglio relief exceptionally well; fibres compress under pressure and hold the ridge |
| Polymer film | Biaxially oriented polypropylene film, surface-coated so ink will adhere | Fully transparent window, integrated holographic and metallic elements, no watermark possible | Takes offset and intaglio on coated areas; ink sits on a coating rather than in fibre, so the tactile feel differs |
| Emergency and improvised stock | Thin wood-pulp paper, card, linen, leather, silk, wood veneer and other substitutes used in crisis issues | Usually none; security is sacrificed for speed and availability | Often offset or letterpress only, frequently one-sided, with poor register |
What is the sequence of a modern print run?
The order is fixed because each stage depends on the one before it: the substrate is made first with watermark and thread already inside, then offset lays the background, then intaglio adds the engraved relief, then the sheets are inspected, then letterpress overprints serials and seals, and finally the sheets are cut, counted, banded and shipped. Ink from each pass has to set before the next runs, so the stages are separated in time rather than run back to back on one line.
| Stage | Process | What it adds | Why it happens here |
|---|---|---|---|
| 1. Substrate manufacture | Papermaking or polymer film production | Watermark, security thread, embedded fibres, or the polymer window and its coating | These features form in the material itself and cannot be added by any press afterwards |
| 2. Offset background | Offset lithography, both sides usually printed in one pass | Underprint tints, guilloche, rainbow blends, see-through register halves | Front-to-back registration is only achievable when both sides print together |
| 3. Intaglio | Engraved plates under very high pressure | Portrait, vignettes, main lettering, latent images, tactile marks | Needs a set, stable coloured ground to press into, and must sit visually above it |
| 4. Screen application | Screen printing on targeted areas | Optically variable ink, iridescent stripes, dynamic and invisible inks | Thick ink films would be crushed and smeared by a later intaglio pass |
| 5. Inspection | Automated and manual sheet examination | Rejection of misregistered, smeared or short-inked sheets | Cheaper to reject before unique numbers are committed to a sheet |
| 6. Letterpress numbering | Raised type with advancing numbering boxes | Serial numbers, prefixes, seals, series dates, overprints | The only stage where the image changes on every impression |
| 7. Finishing | Cutting, counting, banding, packing | Individual notes in sequenced bricks and straps | Replacement notes are substituted here to keep the count intact |
Not every note takes every stage, and that is the most useful thing to know when you meet an unfamiliar issue. A design with no printed background skips offset entirely. Many nineteenth and early twentieth-century notes are intaglio and letterpress only. Most emergency issues are offset or letterpress only, with no engraving at all. Reading which stages a note went through tells you a great deal about the conditions it was made under.
Grading interacts with the print run in ways that are easy to miss. Sheet position affects inking and pressure, so notes cut from the edge can show different coverage from centre notes, and centring is a graded criterion precisely because it is a print-run artefact rather than a circulation artefact. Our comparison of graded versus raw banknotes explains how third-party graders weigh production characteristics against wear.
Frequently asked questions
Why can you feel the ink on a real banknote?
The raised feel comes from intaglio printing. The design is engraved into a steel plate, ink fills the recessed lines, the plate surface is wiped clean, and the sheet is forced into those grooves under very high pressure. The ink lifts out and stands above the paper as a physical ridge. Run a fingernail across a portrait and you are feeling that ridge, which flat printing cannot reproduce.
What is the difference between intaglio and offset printing on a banknote?
Intaglio cuts the image into the plate and presses the sheet into it, producing raised ink you can feel. Offset lithography works from a flat plate, transfers ink to a rubber blanket and then to the sheet, and lies completely smooth. Intaglio carries the portrait, main lettering and engraved detail. Offset carries the background tints, guilloche patterns, rainbow blends and the see-through register.
Are serial numbers printed at the same time as the rest of the note?
No. Serial numbers are added last, by letterpress, after the background and engraving are complete and the sheets have been inspected. Letterpress numbering boxes advance mechanically with each impression, so every sheet receives numbers no other sheet has. Everything printed earlier is identical across the whole run. This is also why damaged sheets are replaced with specially marked replacement notes rather than reprinted with duplicate numbers.
What is banknote paper made of?
Banknote paper is rag paper made from cotton, often blended with linen or other textile fibres, and it contains no wood pulp. United States currency paper is 75 percent cotton and 25 percent linen (Bureau of Engraving and Printing). That fibre structure is what allows a true watermark and an embedded security thread to form during papermaking, and it is why a note survives handling and moisture far better than ordinary paper.
Are polymer banknotes printed the same way as paper ones?
Largely yes. Polymer notes still take offset and intaglio printing on coated areas, so they can carry raised engraved elements. The difference is the substrate. Polymer film has no fibre structure, so it cannot hold a watermark or an embedded thread. Instead it carries a fully transparent window and integrated holographic elements. Australia issued the first modern polymer note in 1988 (Reserve Bank of Australia and CSIRO).
Planet Banknote is a family-owned dealership in Sarasota, Florida, founded in 2021. Every note is sourced direct from mints, central banks, and authorized distributors, inspected through our Planet Banknote Verified process, and ships with a free Certificate of Authenticity. US orders ship free via USPS Priority, and every order includes a free bonus gift.
Once you can name the four passes, the rest of the library reads differently. Continue with banknote security features to see what each layer looks like on a genuine note, how to spot a counterfeit banknote for the checks that follow from the printing sequence, and how to store banknotes to protect the intaglio relief you just learned to feel for. New collectors should start with how to collect world banknotes. When you are ready to hold an example, browse certified graded banknotes or United States banknotes, where inventory and pricing vary with what we have on hand.