Definition

1. Adjective:
   • Treated or combined with bichromate: Describes a material, typically a surface or a solution, that has been processed with or contains bichromate (also called dichromate), a chemical compound containing the Cr₂O₇²⁻ ion. This treatment is often used in historical photographic and photomechanical processes.

Usage

• The term is primarily used in technical, historical, and artistic contexts, particularly when discussing early photographic techniques, printmaking, or certain chemical treatments.
• It functions as an adjective to modify nouns like "paper," "gelatin," "colloid," or "process."

Examples

• Adjective:
  • The 19th-century photographer prepared a bichromated gelatin plate for the photogravure process.
  • In this archive, we found several prints made using bichromated collodion.
  • The solution must not be bichromated for this modern safety protocol.

Advanced Usage

• "bichromated colloid": A light-sensitive mixture used in processes like gum bichromate printing, where a colloid (e.g., gum arabic) is made photosensitive by the addition of a bichromate.
  • Artists value the painterly quality of prints made with a bichromated colloid.
• "bichromated process": Refers to any photographic or printmaking technique that relies on the light-sensitivity of bichromated compounds.
  • The cyanotype is simpler and less toxic than many bichromated processes.

Variants and Related Words

• Bichromate (n): Another term for dichromate, a salt of dichromic acid (e.g., potassium bichromate).
• Dichromated (adj): A more modern and chemically precise synonym for "bichromated."
• Bichromate process (n): A general term for techniques using bichromated materials.

Synonyms

• Dichromated: Treated with dichromate. (This is the preferred term in modern scientific contexts.)
• Chromated: Treated with a chromium compound (a broader, less specific term).

Notes on Meaning

• The term is highly specific and technical. Its use is largely historical or confined to specialized fields like photographic conservation, historical printmaking, and chemistry.
• The prefix "bi-" in "bichromate" indicates the presence of two chromium atoms, though "dichromate" is the standard IUPAC name. Therefore, "bichromated" and "dichromated" are functionally synonymous.

Adjective

1. treated or combined with bichromate