Hot metal typesetting
Lead rate is a process for production of printing plates for letterpress printing. Individual letters or single letters that are cast in a lead-tin -antimony alloy, are assembled to form the complete shape of a side. After the impression the printing form can again into their individual parts disassembled ( " stored ") and the letters are re- used. Prerequisite for this is the single letters set in the hand set or with the Monotype typesetting machine. Machine set with cast lines as provide him the Linotype or Ludlow casting machine is melted down after use again and re-cast.
The basis for this technique was created in 1440 by Johannes Gutenberg, the newly developed printing with movable type or " mobile type printing ". However, there was the pressure of reusable and metal letters before Gutenberg. Finds from China ( see also related department and documentation in the Mainz Gutenberg Museum ) and Korea lead to the conclusion that there exists a so-called Nacherfindung the system in Europe. Again, the use of soft metals such as lead and tin, as well as the construction of a die with replaceable Gießinstrumentes definitely. Also, the set of techniques differ in that the Asian set to strings ( image emblematic words ) and the European is based on separate letters.
Lead record types
One distinguishes the hand set - the oldest form, which largely disappeared until the 1970s - and the machine set. The machine set is further divided into three different functional principles. Typesetting machines use the font types from the hand set ( eg the Kastenbein typesetting machine ). Excluding the line is still running or subsequently corrected by hand. In the single-letter set and casting machine Monotype new letters are cast from matrices. In line-casting machines (eg Linotype typesetting machine, typographer ), there is the signature line of a single piece. Therefore, a faulty line must be set and poured new to linotype. Exclusion and formatting is handled in the first movement step and are not be corrected afterwards. The various techniques have been often used side by side in parallel. The caster could (up to 1500 characters ) far surpassed with 6,000 characters per hour, the rate performance of a hand translator. Later these machines record types, were replaced by more recent compositional techniques, such as the photo set or the computer set.
Translators language and mathematics
Many of typographic terms and rules from the time of the lead set are still valid and have even been transferred to the desktop publishing. From the time of the hand- set, many concepts and units of typography have received. With the change from metal type to digital set the fictional Bleilaus is threatened with extinction.
A special feature of the hand set mathematics was, for example, the systemic arithmetic. It is always possible to produce through systematic combination of font and exclusion material an accurate rectangle. The base of the typographic system is the typographic point and the dodecahedral computational model (point, Cicero = 12 pt, concordance = 4 Cicero). Starting with a thickness of ½ point up to the size of several concordances all font sizes and spacers are seamlessly combined.