inkA liquid or paste, containing dyes or pigments, used for writing or printing. Writing ink dates from the 3rd millennium BC in China and Egypt. The most common today is blue-black permanent ink, made by dissolving gallic acid, iron (II) sulfate, and tartaric acid in water. Since the blue-black color is produced only when the ink dries, a dye is usually added to color the ink during writing. In ballpoint inks, dyes are dissolved in glycols and other liquids, and wetting agents added. Black waterproof India ink is a suspension of carbon particles stabilized by gelatin, glue, etc. Carbon black is also the pigment used in black printing ink. Printing inks – diverse in their composition and uses – are viscous pastes made by grinding pigments with varnishes or petroleum solvents, and contain various additives for printability and drying speeds. Related categories INDUSTRIAL CHEMISTRY• ORGANIC CHEMISTRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |