Letterpress & Thermography Printing

Letterpress printing — how it works

Letterpress is the oldest commercial printing process — invented by Gutenberg in the 1440s and the dominant printing technology for 500 years. In letterpress, the image area is raised above the non-image surface. Ink is applied to the raised surface by rollers, and paper is pressed against it to receive the impression. The distinctive characteristic of letterpress is the impression — the pressure that transfers ink also debosses the paper slightly, creating a tactile "kiss" or dent visible especially on thick, soft papers.

Modern letterpress revival (2000s–present) uses photopolymer plates — flexible plastic plates on which the image is exposed using UV light and a film negative, then the non-image areas are washed away to leave a raised surface. Photopolymer plates have largely replaced hand-set metal type and magnesium dies for commercial letterpress work, making setup faster and enabling fine halftone reproduction impossible with hand-set type.

Letterpress in India — the wedding invitation market

Letterpress nearly disappeared in India during the offset revolution of the 1970s–1990s. It has experienced a significant revival since the 2010s, driven almost entirely by the premium wedding invitation market. Wedding invitations are a high-value, highly personal print product where the tactile impression of letterpress on thick cotton or textured paper creates a perceived value that no other process delivers at comparable cost.

In India (2026), letterpress for premium invitations and stationery is concentrated in Delhi, Mumbai, and Ahmedabad — typically small print shops that operate 1–3 Heidelberg Platen presses (the cast-iron clamshell press that became the global standard for letterpress from the 1950s) alongside newer tabletop presses like the Pilot or Arab. Ink is usually oil-based or soy-based process or custom mixed Pantone spot colours. Pantone 877 metallic silver is the most requested letterpress ink for wedding invitations.

Letterpress design rules

• Minimum type size: 8pt for body text is the practical minimum. Serifs in small type tend to fill in under the impression pressure. Sans-serif or slab-serif typefaces are more reliable at small sizes.
• Fine hairlines: Lines below 0.25pt hairline width will not hold reliably in photopolymer plates or under impression pressure. Design minimum 0.5pt line weight for fine rule work.
• Coverage: Letterpress works best with relatively low ink coverage. Full-coverage backgrounds (large solid areas) require very even impression and may show mottle or uneven inking. Letterpress is ideal for type-dominant designs.
• Paper: Deep impression requires soft, thick paper — uncoated cotton paper (Crane, Crane's Lettra), uncoated heavy stock (Colorplan 350gsm, Curious Cotton 320gsm), or handmade papers. Coated papers hold impression poorly. Minimum 300gsm for visible impression depth.
• Colours: Each colour requires a separate pass through the press. 2-colour letterpress is standard. 3-colour is possible but registration between passes is challenging. 4-colour CMYK letterpress is specialty work done by very few practitioners.

Thermography — raised printing without engraving cost

Thermography is a printing process that produces a raised, glossy, tactile finish by dusting freshly printed wet offset or letterpress ink with a thermographic powder, then heating the printed sheet in an oven. The powder fuses with the wet ink and swells as it melts, creating a raised surface that resembles engraving at a fraction of the cost.

Thermography is the dominant premium finish for business cards in India. "Raised printing" on business cards is virtually always thermography — true engraving (intaglio) is available but costs 5–10× more and requires specialised equipment unavailable to most commercial printers.

How thermography works — the process

1. The design is printed in standard offset or letterpress using slow-drying ink (modified oil-based ink with delayed drying)
2. Immediately after printing, the sheet passes under a powder hopper that dusts thermographic powder over the wet ink. The powder adheres only to the wet ink, not to dry paper areas.
3. Excess powder is vacuumed off the paper surface
4. The sheet passes through a heated oven (approximately 180–220°C) — the powder melts, fuses with the ink, and swells to create a raised, glossy dome
5. The sheet cools, leaving a permanent raised finish

Thermography powder types

• Gloss/high-gloss: Standard finish — clear, translucent, or coloured powder. Ink colour shows through the clear powder.
• Matte: Non-glossy raised finish — less common, more subtle than gloss
• Metallic: Powder contains metallic particles — gold, silver, bronze. Combined with a metallic Pantone ink for maximum effect.
• Coloured opaque: The powder itself is the colour — useful when printing on coloured stock
• Fine/ultra-fine: Finer particle size for detailed work, small type. Standard powder can fill in fine serifs and small text — ultra-fine maintains detail better.

Thermography limitations

• Cannot be laminated after thermography — the raised surface prevents proper lamination adhesion
• Cannot be used under foil stamping without careful sequence planning
• Minimum practical type size approximately 6pt — smaller text fills in
• Not suitable for fine line illustration work — line quality is softer than offset
• Heat sensitivity — thermographed cards can stick together if stored in a hot car. This is a genuine issue in India's climate.

Engraving (intaglio die-stamping) for stationery

True engraving — intaglio die-stamping — is the opposite of letterpress: the image is recessed into a steel die, ink fills the recesses, and paper is pressed against the die under extreme pressure to lift out the ink. The ink sits on top of the paper surface with a distinctly sharp, hard-edged quality that thermography cannot replicate. Running a finger across engraved text produces resistance — the same tactile property as banknote intaglio, which is engraving at its most demanding.

In India (2026), very few commercial printers offer genuine engraving. The process requires a steel die (cut by skilled engravers or by chemical etching) and a specialised engraving press with the ability to exert the required tonnage. Engraving is used for: embassies and government stationery, corporate letterheads for senior executives, premium wedding invitations for very high budgets, and some pharmaceutical labels requiring the specific ink-stand quality.