An ink ribbon or inked ribbon is an expendable assembly serving the function of transferring pigment to paper in various devices for

impact printing In computing, a printer is a peripheral machine which makes a persistent representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers. Differ ...

. Since such assemblies were first widely used on

typewriter A typewriter is a mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of keys, and each one causes a different single character to be produced on paper by striking an inked ribbon selectivel ...

s, they were often called typewriter ribbons, but ink ribbons were already in use with other printing and marking devices. Ink ribbons are part of standard designs for hand- or motor-driven typewriters,

teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Initia ...

stenotype A steno machine, stenotype machine, shorthand machine, stenograph or steno writer is a specialized chorded keyboard or typewriter used by stenographers for shorthand use. In order to pass the United States Registered Professional Reporter test, a ...

machines, computer-driven printers, and many

mechanical calculator A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators wer ...

s. Thousands of varieties of ink ribbons and ribbon cartridges have been produced, and are available from stationery suppliers.

Description

The prototypical assembly consists of a length of a medium, either pigment-impregnated woven ribbon or pigment-coated

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

tape, and a transport mechanism involving two axles. At any given moment, most of the length of the medium is wound as a close-spaced

spiral In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point. Helices Two major definitions of "spiral" in the American Heritage Dictionary are:

Multi-strike (fabric) ribbons

Woven fabric typewriter ribbons were the first kind to be developed. With them, the pigment is an

ink Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, reed pen, or quill. Thi ...

that dries on typing paper but not on the ribbon, and the ribbon is mounted at each end to a

flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of an iron beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer of ...

d reel whose hub engages with one of the axles. Only the axle onto which the ribbon is winding is driven, and the ribbon assembly is intended to work with an axle-driving mechanism that reverses the direction of rotation when the undriven axle reaches the point where there is almost no ribbon left wound around it. Thus, the full length of the ribbon shuttles back and forth between reels, and each position along it is struck twice in each cycle of the ribbon's motion (once in the right-to-left phase and once in the left-to-right). This process can proceed indefinitely, until a depleting ink supply causes the typed characters to become unacceptably faint. Reversal of the ribbon was often controlled manually in early machines, but automatic reversal mechanisms became popular later. An operator who judges a ribbon's ink supply to be too depleted typically manually winds the whole ribbon onto the fuller reel, releasing it from the empty one, and discarding the ribbon and the reel it is wound on. It is replaced with a new ribbon that is purchased already wound on a single compatible reel. Typically the attachment between reel and ribbon involves one grommet at each end of the ribbon that pierces the ribbon and engages with a hook on the hub of the corresponding reel. There often is a small grommet or eyelet near each end of the ribbon, which activates an automatic ribbon-reversal feature of the ribbon-advance mechanism. An alternative design encloses two pre-threaded spools within a single disposable ribbon cartridge, eliminating the need to manually thread a messy ink ribbon. Cartridge designs are often used with higher-speed automatic printers, or ribbons with multiple inks used for color printing. Heavy-duty high-speed line printers may use wider ink ribbons, ranging up to the full width of a 132-column printout, nominally . Another alternative design omits the spools, and simply stuffs inked ribbon into a plastic box through a narrow vertical slot, pulling it out the other end as needed. The box and ribbon are proportioned to avoid tangling inside the box. The ends of the ribbon are joined in an endless loop, so that a ribbon reversing mechanism is not needed. Some of these spool-less cartridge designs make a half-twist in the ribbon before joining it up into a loop, resulting in a

Mobius strip Moebius, Möbius or Mobius may refer to: People * August Ferdinand Möbius (1790–1868), German mathematician and astronomer * Theodor Möbius (1821–1890), German philologist * Karl Möbius (1825–1908), German zoologist and ecologist * Paul ...

. This is done as a method to distribute wear and ink depletion more evenly throughout the ribbon, to make it last longer. Ink-depleted fabric ribbons can be re-inked to allow re-use, but this is a messy procedure; many used fabric ribbons are instead discarded, along with the spool which they were wound around, or as part of a cartridge assembly. The de facto standard width of typewriter ribbons is , but some ribbon spools are no longer manufactured, requiring owners of vintage machines to re-ink used ribbons and/or to re-spool new ribbon onto their vintage spools. File:Printer dot matrix EPSON VP-500.jpg, Large ink ribbon cartridge installed in a dot-matrix printer File:Ink cartridgee and inside zoom.jpg, Spool-less ink ribbon cartridge with and without cover File:IBM 1403 Printer opened.jpg, Wide ink ribbon can be seen at right of this opened

IBM 1403 The IBM 1403 line printer was introduced as part of the IBM 1401 computer in 1959 and had an especially long life in the IBM product line. Description The original model can print 600 lines of text per minute and can skip blank lines at up to ...

line printer

Single-pass (polymer) ribbons

The IBM Selectric typewriter required ribbons of polymer (plastic) tape and popularized their use, even with other manufacturers. This type of ribbon is sometimes called a "carbon ribbon". With this newer medium, the entire impacted area of the pigment coating adheres to the paper and transfers from the ribbon, producing typed copy with greater uniformity of character shape, reflecting a sharper contrast between the unmarked paper and the pigmented characters compared to cloth ribbons. This produces a clearer, easier-to-read printed image which looks more "professional" in printed documents. However, the full-depth transfer of the pigment renders multiple passes over the same length of the ribbon unworkable, so the assembly is discarded after a single pass through its length. Because polymer tape is much thinner and more easily tangled than cloth ribbon, it usually is packaged in an enclosed cartridge with two spools, eliminating the need to manually thread a delicate ribbon onto an empty spool. Deducing what has been typed by inspection of the used ribbon is far more practicable and reliable than with a cloth ribbon, so some users ensure secure destruction (shredding) of discarded one-time ribbons in order to prevent unintended disclosure of typed documents. File:Typewriter ribbon of polymer tape-4245.jpg, Typewriter ribbon cartridge with polymer tape File:Typewriter ribbon of polymer tape-4247.jpg, Ribbon cartridge with cover removed File:Typewriter ribbon of polymer tape-4253.jpg, Used polymer ribbon reveals what has been typed

History

There were many different schemes to supply ink to early typewriters, including ink-soaked rollers, ink pads, and rubberized cloth strips. Eventually, ink ribbons emerged as the de facto standard method of supplying ink for impact printers of all types.

References

{{Authority control Typewriters