SF-02
Recess engraving (intaglio)
The house technique: ink carried in lines cut below the surface of a steel plate and pressed into damp paper under great force.
Recess engraving (intaglio) ×4
Specification
- House code
- SF-02
- Method
- Intaglio, recess-engraved from a steel plate
- Apparent at
- ×4
- Deters
- Flat reproduction by scanning, photocopying or digital press.
- The recipient’s check
- Run a fingertip across the engraved lines. They stand up off the paper and you can feel them. Tilt the sheet to a raking light and the ridges cast their own small shadows.
Intaglio is the opposite of every printing process most people have met. In letterpress and offset the image stands proud of the plate; in intaglio it is cut into it. The plate is inked, the surface is wiped clean, and ink remains only in the incised lines. Damp paper is then pressed onto the plate under a pressure measured in tonnes, and the paper is driven down into the lines to lift the ink out.
The result is a document with relief. The ink sits on a ridge above the paper surface, and the plate leaves a debossed rectangle — the plate mark — around the whole image. Both are consequences of physics rather than of design, and both are absent from anything produced by a process that only ever puts ink flat onto a surface.
Why it endures
Recess engraving is the oldest security feature still in daily commercial use, and it has survived every generation of reproduction technology for the same reason: a copy of an engraving is a picture of relief, not relief. It is also, quite simply, the most beautiful way to print a line, which is why it remained the choice for diplomas and share certificates long after the security argument alone would have justified something cheaper.
Our plates are cut in the plate room at Foundry Row and kept in the house archive for the life of the client relationship.