bichromate process: meaning, definition, pronunciation and examples
LowSpecialist/Technical
Quick answer
What does “bichromate process” mean?
A photochemical printing or engraving process that uses a bichromate salt, typically potassium or ammonium bichromate, as a sensitizing agent.
Audio
Pronunciation
Definition
Meaning and Definition
A photochemical printing or engraving process that uses a bichromate salt, typically potassium or ammonium bichromate, as a sensitizing agent.
A historical photographic or printmaking technique where a surface coated with a mixture of a bichromate and a colloid (like gelatin or gum arabic) becomes insoluble when exposed to light, allowing for the creation of images, photolithographic plates, or resist patterns.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning. The chemical compound itself is more commonly called 'dichromate' (especially in AmE scientific contexts), but the process name 'bichromate process' is standard in both varieties.
Connotations
None beyond the technical/historical domain.
Frequency
Equally rare in both varieties, confined to very specific technical fields.
Grammar
How to Use “bichromate process” in a Sentence
The [NOUN] uses the bichromate process.They [VERB: created/printed/produced] it via the bichromate process.The [NOUN: image/print/plate] was made by the bichromate process.Vocabulary
Collocations
Examples
Examples of “bichromate process” in a Sentence
verb
British English
- The plate was then bichromated and exposed.
American English
- They bichromated the gelatin solution before coating the paper.
adjective
British English
- The bichromate-sensitised paper was handled under safelight.
American English
- A bichromate-coated aluminium plate served as the printing matrix.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in historical texts, art history papers, and histories of photography/printing technology.
Everyday
Never used.
Technical
Used in specialized discussions among printmakers, photographic historians, conservators, and in technical manuals for historical processes.
Vocabulary
Synonyms of “bichromate process”
Strong
Neutral
Weak
Vocabulary
Antonyms of “bichromate process”
Watch out
Common Mistakes When Using “bichromate process”
- Misspelling as 'bichromate proces' (missing 's').
- Confusing it with the 'cyanotype process' (which uses iron salts, not chromium).
- Using it as a verb (e.g., 'to bichromate' is rare; prefer 'to use the bichromate process').
FAQ
Frequently Asked Questions
It is primarily used by fine art photographers and printmakers specializing in historical or alternative processes, not in commercial printing.
Chemically, they refer to the same salts (e.g., K₂Cr₂O₇). 'Bichromate' is an older name, still common in process names like 'bichromate process'. 'Dichromate' is the modern IUPAC-preferred term in pure chemistry.
Bichromate/dichromate salts are toxic, carcinogenic, and strong oxidizers. They pose health and environmental risks, requiring careful handling, disposal, and safety equipment like gloves and ventilation.
Yes, the 'gum bichromate' process is a well-known type used for creating painterly photographic prints.
A photochemical printing or engraving process that uses a bichromate salt, typically potassium or ammonium bichromate, as a sensitizing agent.
Bichromate process is usually specialist/technical in register.
Bichromate process: in British English it is pronounced /baɪˈkrəʊmeɪt ˈprəʊses/, and in American English it is pronounced /baɪˈkroʊmeɪt ˈprɑːses/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: 'BI' (two) + 'CHROMATE' (chromium compound) = a process using a double-chromium salt to fix an image with light.
Conceptual Metaphor
LIGHT AS A HARDENER: Light exposure transforms a soft, soluble coating into a hard, fixed image.
Practice
Quiz
What is the primary chemical agent in the bichromate process?