In printing and typography, hot metal typesetting (also called mechanical typesetting, hot lead typesetting, hot metal, and hot type) is a technology for typesetting text in letterpress printing. This method injects molten type metal into a mold that has the shape of one or more glyphs. The resulting sorts or slugs are later used to press ink onto paper. Normally the typecasting machine would be controlled by a keyboard or by a paper tape.
It was the standard technology used for mass-market printing from the late nineteenth century until the arrival of phototypesetting and then electronic processes in the 1950s to 1980s.[1][2][3]
History
Hot metal typesetting was developed in the late nineteenth century as a development of conventional cast metal type.[4] The technology had several advantages: it reduced labour since type sorts did not need to be slotted into position manually, and each casting created crisp new type for each printing job. In the case of Linotype machines, each line was cast as a robust continuous block (hence "line o'type") which was useful for rapid newspaper printing.
Types of typesetting
Two different approaches to mechanising typesetting were independently developed in the late 19th century. One, known as the Monotype composition caster system, produced texts with the aid of perforated paper-ribbons. Each character was cast separately. These machines could produce texts also in "large-composition" up to 24 point.
The Super-caster, another machine produced by Monotype, was similar in function to the Thompson, Barth, pivotal and others casters but designed to produce single type (including even larger sizes) for hand setting.
The other approach was to cast complete lines as one slug, usually comprising a whole line of text.
Of this system there were at least five manufacturers:
The Linotype and similar Intertype machines came out with paper tape and electronic automation near the end of their lifecycles, which allowed for the news wire services to send breaking news to remote newspaper offices for prompt setting into late editions.
While the other machines were operated by (non-QWERTY) keyboards, in the Ludlow Typograph the matrices for each line were assembled in a stick by hand. This machine was able to cast display body sizes that other mechanical composition systems were unable to produce. In this way headings could be produced to complement text produced on other machines. It also used the same alloy as Linotype machines, so was a useful adjunct to page makeup for newspapers as, when a print run was completed, all the metal could be remelted at once, without having to be separated or the type from the headings redistributed back into case.
The success of these machines lay in different fields. The Monotype caster was more popular for bookwork that required the ability to make manual corrections and edits while the slug casting systems found success in newspaper production, where speed of production and 'make ready' for print was essential.
Another essential difference between Monotype and the "slug"-producing machines is that a Monotype machine functions with a minimal set of matrices. Each character needs one matrix. Linecasters cannot function this way, and these systems need quite large magazines of matrices to be able to set a complete line of text with the usual character repetitions. Indeed, the nominal 90-channel magazine of a linecaster really has 91 total channels, with the first two channels allocated to the lower case 'e', and with these matrices being alternately selected from channel 0 or channel 1, for alternate lines of cast type.
Additionally, Monotype must use a punched paper tape, and the "reading frame" is always backwards (right-to-left) in order to achieve justification, as justification is not an inherent capability of the machine (however, "flush left" is an inherent capability). Whereas Linotype may use a punched paper tape, although this option is seldom-used outside of daily newspapers, and whether a tape is used, or not, the "reading frame" is always forwards (left-to-right), with justification being an inherent capability of the machine (and, "flush right", "centered" and "flush left" may be very easily accommodated manually, or automatically using a "quadder" attachment).
The key feature of the Linotype is the use of molds which circulate through the machine in its various stages of operation. One type is a space band (a special two-part sliding wedge) and the other is a letter matrix made of brass. The matrices are stored in one or more magazines on top of the machine (providing the operator with a choice of fonts; these can also be exchanged with other extra magazines as desired) while the space bands are stored in a box closer to the keyboard.
Once a key is pressed, the matrix passes through what is known as the ‘assembler front’, down past a rotating fiber reinforced wheel (known as the star wheel) and into the ‘assembling elevator’ which serves the same purpose as the hand compositor's stick. When the space band key near the keyboard is pressed, one of the space bands drops out of the box and almost directly into the assembling elevator. The assembling elevator (or more commonly just the ‘assembler’) is adjustable for different lengths of line (in picas).
Once the line approaches its correct length, the operator is made aware of this by a bell or other indicator. If the line is ‘loose’ or too short, there is too much ‘white space’ for the space band wedges to fill out the line, and the matrices could possibly turn sidewise or fail to seal against each other as the machine prepares for the casting operation. If the line is ‘tight’ or too long, the elevator carrying the matrices and space bands will not seat properly in front of the mold slot. Both the Linotype and Intertype machines have two important safeties that act during the casting operation – the ‘pump stop’, which comes into play on loose lines, and the ‘vise automatic', which comes into play on tight lines. Both scenarios, if not stopped by these safety features, usually result in a “squirt” of molten type metal, encasing the matrices and the elevator in metal in the process. Not only is it time-consuming to clean up after a squirt, a tight line usually has not come down far enough to mate with the slots on the mold face, resulting in damage to the matrices. Therefore, it is considered very poor form for an operator (or the machinist who cared for the machine) to permit this to happen.
When the line is assembled to the correct length, the operator presses down on a lever which raises the assembling elevator up into the delivery channel and starts the automatic casting cycle. The delivery channel transfers the matrices out of the assembler and into the first elevator. The first elevator then descends to a position in front of the mold, and if the elevator has not descended fully by the time the machine starts the process of aligning the matrices (most often caused by a ‘tight’ line), the first of the two safeties, the vise automatic, brings the machine to a full stop before the supporting lugs on the matrices are crushed by the mold. Once the matrices are in proper position, two actions take place in sequence: the matrices are aligned vertically and face-wise while a bar rises from below to force the movable sleeves on the space bands upwards to cause them to fill out the line to the exact width of the mold. If the justification bar has made a full cycle and the line is still not fully justified, the second safety, the pump stop, prevents the plunger in the metal pot from going down. The space bands were an important feature of this machine, providing automatic justification of each line by equally adjusting the white space between each word. Since the type used was proportional and not fixed in width, solving this justification problem mechanically was very important. Some later models had a feature that permitted the lines to be cast with the alignment to either left, right or centered. Operators running earlier models would use special ‘blank’ matrices (in four sizes) to manually create the proper amount of whitespace beyond the space bands’ range.
With the matrices aligned and the space bands set to the correct measure, the machine then ‘locks up’ the line with great force and the plunger injects the molten type metal into the space created by the mold cavity and the assembled line. The machine then separates the mold disk (carrying the freshly cast slug), the metal pot, and the first elevator. The mold disk then turns to present the line at the ejecting position, in the process passing by a knife that trims the base of the slug to type height (0.918″ on US machines). The slug is then forced through an adjustable pair of knives to trim the slug to the proper body height before sliding down into a ‘galley’ of finished lines next to the operator. Depending on the model of machine, the mold disk could have four (standard), six, or two molds, giving the operator his choice of line lengths and body sizes.
As the mold disk is turning, the first elevator simultaneously rises to its upper position and the space bands and matrices are vertically aligned in preparation for the second transfer. The matrices have a series of teeth in a V-shaped notch on top, and as the transfer is completed, the matrices slide onto the second elevator bar which carries the matrices by these V-shaped notches. The space bands, having no such notches, remain in the second transfer channel and are soon gathered by two levers and pushed back into the space band box. While the space bands are being pushed into their box, the second elevator continues rising towards the distributing mechanism at the top of the machine, which returns the molds to their proper places in the magazine. At the top of the machine, a lever (the distributor shifter) moves left to get in position to push the incoming line of matrices off the second elevator and into the distributor box. This mechanism feeds the matrices at precise intervals such that they travel between three rotating screws. Each matrix is carried along a notched bar between the three screws until the notches on the bar and matrix match, whereupon the matrix drops down into its proper channel in the magazine.
It was a source of pride for trained operators to boast of being able to ‘hang’ a line – to keep a line waiting in the delivery channel while the machine was casting the previous line and the operator was composing the next one.
The metal pot was kept filled by the operator tossing in small ingots of type metal every few lines, or later, by mechanical feeders that carry large ingots of type metal (and which often carried two ‘pigs’ at a time to be consumed in turn, the operator hanging a fresh one when one was consumed). These feeders are actuated by various methods (by cam, either elevator, or distributor shifter), but the end result is the same – the ingots are fed little by little into the pot, keeping it filled to the correct level.
From time to time, the slug galley is transferred to the composing table to be set in the form, and once the press run is completed and the slugs removed from the form, they are tossed into the ‘hell box’ for remelting into new ingots. At intervals the lead is remelted and the oxidized metal (dross) skimmed off. As part of this process, ‘plus metal’ is added in the form of small ingots to replenish that portion of the alloyed metals that was lost by the formation of dross (by oxidization of the metal in the machine's pot or during the remelting stage). The type metal is poured into ingot molds – small molds for manually feeding the metal pots or larger molds for the metal feeders. (In the latter case, special attention must be given the ‘eye’ end as it has to support the weight of the entire ingot. Failure often results in it dropping into the pot and splashing molten metal everywhere.)
Funded largely by the Ridder newspaper interests, the Intertype Corporation developed (c. 1914) a compatible version of the Linotype machine when the patents ran out and it became quite popular as well. This led to a long-lasting legal fight by the Mergenthaler Linotype Company (who eventually lost).
Various methods were used to power the Linotype / Intertype machines, the most common being a fractional horsepower motor, one wired for single-phase 60Hz alternating current eventually becoming the default offering. To accommodate the customers' requirements, motors were also built to be powered from direct current, 25Hz AC, or 50Hz AC circuits. Also, motors wound for various polyphase circuits (two-phase, 3-phase, wye, delta, etc.) were made available for the customers as well. In a few cases, where electricity was not available, it was possible to drive the machine by a belt connected to a line shaft.
Initially, the metal pot was heated by gas (whether natural or 'manufactured'), but an electric pot was later developed and which became a standard option. As with the motors, the control machinery for the metal pot heaters was produced in a variety of voltages and in direct or alternating current versions. For locations with access to neither gas or electricity, the gas-fired pot could be fitted with a burner kit to allow the use of kerosene or other 'white gas' fuels.
Thus, regardless of the power sources available (within reason), it was possible to install a Linotype (or Intertype) machine in almost any newspaper office, whether in a remote mountain community or a downtown office in an urban metropolis.
Typograph and Monoline
These machines were bought out by Linotype, to minimize competition.
Ludlow
A manual linecasting solution known as the Ludlow Typograph also met with success because it was able to cast display type sizes that other mechanical composition systems were unable to produce.
The Ludlow consisted of a very heavy metal table with a flat top about waist high and a depressed slot into which a "stick" was inserted. Underneath was a pot of molten type metal and a plunger. The stick was used to hand compose the lines of type, typically headlines in 18 point or larger with 72 point commonly being available, but the machine could cast type from 4pt to 600pt without a mould change. This was from brass matrix stored in cases on either side of the Ludlow. The cases were not the traditional "California Job Cases" used to set body type, but simpler alphabetically arranged wooden or metal cases, each one containing a given font in a specific size and style such as bold face, italic or condensed. The metal type cabinets were built with inclined drawers for easy access to the matrices.
After a line of type was assembled into the stick a special blocking slug was inserted to seal the end. Then the stick was placed mold side down into the slot on the table, a clamp locked down to securely hold the stick and the Ludlow activated. The plunger would snap down into the pot with considerable force, injecting molten type metal into the mold at a high speed to ensure the mold was filled before the metal solidified. If the stick was not properly filled out or mounted firmly, or the special terminating block was forgotten, a dreaded "splash" would result, often encasing the operator's toes in molten lead and leaving a mess that needed to be peeled off the Ludlow surfaces. Operators were encouraged to wear heavy boots with steel toes and be quick at removing one. It was also not uncommon for some of the type metal to be projected up onto the ceiling, no matter the height. As with the Linotype / Intertype machines, the Ludlow machines were often fitted with metal feeders to keep the pot filled to optimum level.
Towards the end of its life as a common backshop type setter, the Ludlow was often joined by the "Super Surfacer" a specially designed surface plane that would smooth the surface of the freshly cast type and ensure it was exactly type high. A Ludlow slug was just the letters overhanging a central spine about 12 points wide (T-shaped viewed from the end). It needed to be bolstered by Elrod slugs on either side for support. The number of slugs above and below the central spine could adjust the white space above and below the type making it a very flexible system for large type.
The Elrod was a machine used to cast rules and spacing material (leading) of a specific width: 1, 1+1⁄2, 2, 3, 4, 6, 12, 18, 24, 30, or 36 point. This was used extensively in page layout and line spacing, that is, adjusting the white space between paragraphs and any other area when small bits of white space were needed. Large areas of white space were created by wooden or later metal blocks called 'furniture'. Smaller odd areas were filled with square or rectangular blocks in various point sizes called quads.
All these line-casting machines used various alloys near the eutectic point and which typically consisted of approximately 4% tin and 12% antimony and the balance being lead. These alloys were proportioned such that the type metal would solidify as rapidly as possible at the lowest possible freezing point.
Monotype
A Monotype composition case showing bronze matrices struck from steel punches
The Monotype System took a different direction in hot metal typesetting, with the ability of the Composition Caster to cast loose type using a paper tape-operated automatic casting machine. The paper tape would be first generated on a keyboard and then used to cast the type; the tape could be stored for future casting for subsequent editions. This was a popular system for book work. Text was produced completely aligned, with all spaces in each line exactly the same width. Corrections and complex work could be done on the text by hand after the bulk of the text had been set by machine. The Super Caster and Orphan Annie were used to cast fonts of loose type for hand setting as well as spacing material and patterned rules.
This type was most times made of an alloy (8-10% tin, 15-20% antimony) slightly harder than the line casting alloys but was not as hard as the foundry type used for hand setting of loose letters. This allowed reasonable print runs or conversion to stereotypes for longer print runs. But these machines could produce type with all possible alloys, when needed.
The used type, like the slugs from line casters, was re-melted when no longer needed. Each time remelting caused some loss of tin and antimony, through oxidation. This loss needed to be monitored and compensated.
The Monotype Corporation survived the demise of the hot metal typesetting era by selling digital type.
Transition
Towards the end of its life, hot metal composition in newspapers was kept alive by the proof press. As each page was set and locked up, it was moved on a turtle (a rolling table with an accurately flat steel surface)[5] to the manual proof press, where it was hand inked and a single very high quality proof was pulled. This proof could then be photographed and converted to a negative.
Black paper was inserted before the proof was photographed for each of the photos on the final page to create clear windows in the negative. The separately made halftones would be taped into these clear windows on the negative. This negative could then be used to expose the photosensitized printing plate for an offset press. In this way the heavy investment in hot metal typesetting could be adapted to the newer offset technology during a transition period.
Another synergy and transition mechanism was using paper tapes made for TTS systems (linotype) and monotype tapes directly by the photo typesetter system.
These tapes could be read and processed by many, maybe most optical setting systems. This allows avoiding actual use of metal, while preserving some of the value and investment in the "typesetting" and communication side of hot metal. Such systems were widely used in the later years of hot metal, and optical typesetting systems kept supporting and further developing TTS standard, alongside similar systems for most of the optical typesetting era.
Comparison to successors
The nature of text printed via the hot-metal method is notably different from that produced by the phototypesetting processes that followed it. As the lead type used to print (letterpress) a page had been directly formed from the type matrix, a good fidelity to the original was achieved. Phototypesetting suffered (at least in its early days) from many problems relating to optical distortion and misalignment. These disappointing results were a thorn in the sides of many authors and readers (especially of complex or mathematical texts that had many small sub- and superscripts). A desire to re-create the aesthetic qualities of hot lead spurred Donald Knuth to create one of the first general-purpose digital typesetting programs, TeX.
Although not technically typesetting, stereotyping (electrotype or nickeltype) could be used to cast a reproduction of an entire typeset page (or pages imposed in a forme) using a mold made with an impression using flong (similar to papier-mâché). The ensuing casting could be made curved for use on a rotary press or flat for the slower flat-bed presses. This technique was often used in newspaper production.
Related Research Articles
The Mergenthaler Linotype Company is a corporation founded in the United States in 1886 to market the Linotype machine, a system to cast metal type in lines (linecaster) invented by Ottmar Mergenthaler. It became the world's leading manufacturer of book and newspaper typesetting equipment; outside North America, its only serious challenger for book typesetting was the Anglo-American Monotype Corporation.
In printing, type metal refers to the metal alloys used in traditional typefounding and hot metal typesetting. Historically, type metal was an alloy of lead, tin and antimony in different proportions depending on the application, be it individual character mechanical casting for hand setting, mechanical line casting or individual character mechanical typesetting and stereo plate casting. The proportions used are in the range: lead 50‒86%, antimony 11‒30% and tin 3‒20%. Antimony and tin are added to lead for durability while reducing the difference between the coefficients of expansion of the matrix and the alloy. Apart from durability, the general requirements for type-metal are that it should produce a true and sharp cast, and retain correct dimensions and form after cooling down. It should also be easy to cast, at reasonable low melting temperature, iron should not dissolve in the molten metal, and mould and nozzles should stay clean and easy to maintain. Today, Monotype machines can utilize a wide range of different alloys. Mechanical linecasting equipment uses alloys that are close to eutectic.
Typesetting is the composition of text for publication, display, or distribution by means of arranging physical type in mechanical systems or glyphs in digital systems representing characters. Stored types are retrieved and ordered according to a language's orthography for visual display. Typesetting requires one or more fonts. One significant effect of typesetting was that authorship of works could be spotted more easily, making it difficult for copiers who have not gained permission.
The Linotype machine is a "line casting" machine used in printing which is manufactured and sold by the former Mergenthaler Linotype Company and related companies. It was a hot metal typesetting system that cast lines of metal type for one-time use. Linotype became one of the mainstays for typesetting, especially small-size body text, for newspapers, magazines, and posters from the late 19th century to the 1970s and 1980s, when it was largely replaced by phototypesetting and digital typesetting. The name of the machine comes from producing an entire line of metal type at once, hence a line-o'-type. It was a significant improvement over the previous industry standard of letter-by-letter manual typesetting using a composing stick and shallow subdivided trays, called "cases".
Etaoin shrdlu is a nonsense phrase that sometimes appeared in print accidentally in the days of "hot type" publishing because of a custom of type-casting machine operators to fill out and discard lines of type when an error was made. It appeared often enough to become part of newspaper lore – a documentary about the last issue of The New York Times composed using hot metal was titled Farewell, Etaoin Shrdlu. The phrase "etaoin shrdlu" is listed in the Oxford English Dictionary and in the Random House Webster's Unabridged Dictionary.
An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of shaping, such as cold/hot working, cutting, or milling to produce a useful final product. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods. Precious metal ingots can be used as currency, or as a currency reserve, as with gold bars.
Phototypesetting is a method of setting type which uses photography to make columns of type on a scroll of photographic paper. It has been made obsolete by the popularity of the personal computer and desktop publishing which gave rise to digital typesetting.
In the manufacture of metal type used in letterpress printing, a matrix is the mould used to cast a letter, known as a sort. Matrices for printing types were made of copper.
Monotype Imaging Holdings Inc., founded as Lanston Monotype Machine Company in 1887 in Philadelphia by Tolbert Lanston, is an American company that specializes in digital typesetting and typeface design for use with consumer electronics devices. Incorporated in Delaware and headquartered in Woburn, Massachusetts, the company has been responsible for many developments in printing technology—in particular the Monotype machine, which was a fully mechanical hotmetal typesetter, that produced texts automatically, all single type. Monotype was involved in the design and production of many typefaces in the 20th century. Monotype developed many of the most widely used typeface designs, including Times New Roman, Gill Sans, Arial, Bembo and Albertus.
A type foundry is a company that designs or distributes typefaces. Before digital typography, type foundries manufactured and sold metal and wood typefaces for hand typesetting, and matrices for line-casting machines like the Linotype and Monotype, for letterpress printers. Today's digital type foundries accumulate and distribute typefaces created by type designers, who may either be freelancers operating their own independent foundry, or employed by a foundry. Type foundries may also provide custom type design services.
Spin casting, also known as centrifugal rubber mold casting (CRMC), is a method of utilizing inertia to produce castings from a rubber mold. Typically, a disc-shaped mold is spun along its central axis at a set speed. The casting material, usually molten metal or liquid thermoset plastic, is then poured in through an opening at the top-center of the mold. The filled mold then continues to spin as the metal solidifies.
A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron. However, other metals, such as bronze, brass, steel, magnesium, and zinc, are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed.
Continuous casting, also called strand casting, is the process whereby molten metal is solidified into a "semifinished" billet, bloom, or slab for subsequent rolling in the finishing mills. Prior to the introduction of continuous casting in the 1950s, steel was poured into stationary molds to form ingots. Since then, "continuous casting" has evolved to achieve improved yield, quality, productivity and cost efficiency. It allows lower-cost production of metal sections with better quality, due to the inherently lower costs of continuous, standardised production of a product, as well as providing increased control over the process through automation. This process is used most frequently to cast steel. Aluminium and copper are also continuously cast.
In printing, a stereotype, stereoplate or simply a stereo, is a solid plate of type metal, cast from a papier-mâché or plaster mould taken from the surface of a forme of type. The mould was known as a flong.
In typesetting, a sort or type is a block with a typographic character etched on it, used—when lined up with others—to print text. In movable-type printing, the sort or type is cast from a matrix mold and assembled by hand with other sorts bearing additional characters into lines of type to make up a form, from which a page is printed.
A Ludlow Typograph is a hot metal typesetting system used in letterpress printing. The device casts bars, or slugs of type, out of type metal primarily consisting of lead. These slugs are used for the actual printing, and then are melted down and recycled on the spot. It was used to print large-type material such as newspaper headlines or posters.
Type casting is a technique for casting the individual letters known as sorts used in hot metal typesetting by pouring molten metal into brass moulds called matrices.
News Gothic is a sans-serif typeface designed by Morris Fuller Benton, and was released in 1908 by his employer American Type Founders (ATF). The typeface is similar in proportion and structure to Franklin Gothic, also designed by Benton, but lighter.
The Intertype Corporation produced the Intertype, a hot metal typesetting machine closely resembling the Linotype, and using the same matrices as the Linotype. It was founded in New York in 1911 by Hermann Ridder, of Ridder Publications, as the International Typesetting Machine Company, but purchased by a syndicate for $1,650,000 in 1916 and reorganized as the Intertype Corporation.
The Monotype system is a system for printing by hot-metal typesetting from a keyboard. The two most significant differences from the competing Linotype machine are that
References
↑ Boag, Andrew (2000). "Monotype and Phototypesetting"(PDF). Journal of the Printing History Society: 57–77. Archived from the original(PDF) on 28 March 2016. Retrieved 22 July 2016.
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