What does collotype mean?
Collotype is a photomechanical printing process developed in the nineteenth century for reproducing images with exceptional tonal fidelity. A glass or metal plate is coated with gelatin mixed with a dichromate sensitizer; exposure to light through a negative hardens the gelatin in varying degrees, and when the plate is dampened and inked, the image transfers to paper in continuous tones rather than the dot pattern of halftone screens. Because of this, collotype excelled at reproducing photographs, watercolors, and other artwork where subtle gradations mattered, and it became a mainstay of fine art publishing, facsimile editions, and postcard production into the twentieth century. The word also refers to an individual print made by the process. Today collotype survives mainly as a specialist and archival technique, valued by conservators and collectors, while the term itself appears chiefly in discussions of printing history and rare-book scholarship.
nounA photomechanical printing process in which an image is reproduced from a gelatin-coated plate that hardens in proportion to the light it receives; also a print made by this process.
- The photomechanical printing process that uses a light-hardened gelatin-coated plate to reproduce continuous-tone images without a halftone screen.
- A print or reproduction produced by this process.
"The museum's archive of botanical illustrations was reproduced by collotype, preserving every subtle gradation of tone."
"The publisher chose collotype for the facsimile edition because the process captured delicate washes of ink without visible dot patterns."
"Among the prints donated to the library were several late nineteenth-century collotypes of Japanese woodblock designs."
The plural refers either to multiple instances of the printing process in discussion or, more commonly, to multiple individual prints produced by the process.
"The collection includes several collotypes from the turn of the century."
Before modern offset printing, fine art books were illustrated using a plate coated in hardened gelatin — and no screen of dots, so the results could rival photography itself.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of collotype
The word collotype derives from the Greek 'kolla', meaning glue, combined with '-type' from Greek 'typos', meaning impression or form — a reference to the gelatin (a glue-like substance) that forms the printing surface. The process itself emerged in the mid-nineteenth century from experiments in photomechanical reproduction, notably associated with the French inventor Alphonse Poitevin's work on dichromated gelatin. The same Greek root 'kolla' appears in related words such as colloid, collagen, and collage.
How collotype is actually used
Collotype is a technical term used mainly in printing history, fine-art publishing, and photographic conservation. It carries connotations of high-quality, archival reproduction and is largely historical today, as the process has been superseded by offset lithography and digital printing.
Easily confused with collotype
Collodion is a syrupy solution of nitrocellulose used in early photographic processes, whereas collotype is a gelatin-based printing process for reproducing images on paper.