What is "printing ink"

Ink \Ink\, n. [OE. enke, inke, OF. enque, F. encre, L. encaustum the purple red ink with which the Roman emperors signed their edicts, Gr. ?, fr. ? burnt in, encaustic, fr. ? to burn in. See Encaustic, Caustic.]

1. A fluid, or a viscous material or preparation of various kinds (commonly black or colored), used in writing or printing.

   Make there a prick with ink.
   --Chaucer.

   Deformed monsters, foul and black as ink.
   --Spenser.

2. A pigment. See India ink, under India. Note: Ordinarily, black ink is made from nutgalls and a solution of some salt of iron, and consists essentially of a tannate or gallate of iron; sometimes indigo sulphate, or other coloring matter, is added. Other black inks contain potassium chromate, and extract of logwood, salts of vanadium, etc. Blue ink is usually a solution of Prussian blue. Red ink was formerly made from carmine (cochineal), Brazil wood, etc., but potassium eosin is now used. Also red, blue, violet, and yellow inks are largely made from aniline dyes. Indelible ink is usually a weak solution of silver nitrate, but carbon in the form of lampblack or India ink, salts of molybdenum, vanadium, etc., are also used. Sympathetic inks may be made of milk, salts of cobalt, etc. See Sympathetic ink (below). Copying ink, a peculiar ink used for writings of which copies by impression are to be taken. Ink bag (Zo["o]l.), an ink sac. Ink berry. (Bot.)

   1. A shrub of the Holly family ( Ilex glabra), found in sandy grounds along the coast from New England to Florida, and producing a small black berry.

   2. The West Indian indigo berry. See Indigo.

      Ink plant (Bot.), a New Zealand shrub ( Coriaria thymifolia), the berries of which yield a juice which forms an ink.

      Ink powder, a powder from which ink is made by solution.

      Ink sac (Zo["o]l.), an organ, found in most cephalopods, containing an inky fluid which can be ejected from a duct opening at the base of the siphon. The fluid serves to cloud the water, and enable these animals to escape from their enemies. See Illust. of Dibranchiata.

      Printer's ink, or Printing ink. See under Printing.

      Sympathetic ink, a writing fluid of such a nature that what is written remains invisible till the action of a reagent on the characters makes it visible.

Printing \Print"ing\, n. The act, art, or practice of impressing letters, characters, or figures on paper, cloth, or other material; the business of a printer, including typesetting and presswork, with their adjuncts; typography; also, the act of producing photographic prints.

Block printing. See under Block.

Printing frame (Photog.), a shallow box, usually having a glass front, in which prints are made by exposure to light.

Printing house, a printing office.

Printing ink, ink used in printing books, newspapers, etc. It is composed of lampblack or ivory black mingled with linseed or nut oil, made thick by boiling and burning. Other ingredients are employed for the finer qualities.
--Ure.

Printing office, a place where books, pamphlets, or newspapers, etc., are printed.

Printing paper, paper used in the printing of books, pamphlets, newspapers, and the like, as distinguished from writing paper, wrapping paper, etc.

Printing press, a press for printing, books, newspaper, handbills, etc.

Printing wheel, a wheel with letters or figures on its periphery, used in machines for paging or numbering, or in ticket-printing machines, typewriters, etc.; a type wheel.

n. a semi-solid quick drying ink made especially for use in printing [syn: printer's ink]