subject ni lotis

• Lithography


  A printing process invented by Alois Senefelder in 1798 that uses a chemical process to transfer an image from a stone or metal plate to paper
• Alois Senefelder invented lithography


  1798
• Lithography has become one of the largest industries in the United States, part of the Printing Industry, which is the third largest manufacturing industry in the U.S.
• History of lithography


  1. Invention and early use of the process

  2. Introduction of photography to the process

  3. Addition of the offset press to the process

  4. Revolution of the lithographic plate
• Alois Senefelder


  German actor's son who invented lithography
• Senefelder disliked studying law as his father compelled him to, but had a love for the theatre and became successful at writing plays
• Senefelder sought a less costly method of reproducing copies of his plays, which prompted him to invent lithography
• Lithography


  A chemical printing process based on the principle that grease repels water
• Senefelder designed a press that featured automatic dampening and inking of the plate in 1817
• Lithography became popular throughout the world, including the United States, as it was an easy medium for artists to reproduce their work
• The first lithograph appeared in the United States


  1819
• Currier and Ives were the best-known American lithographic printmakers of the time
• By 1871, there were at least 450 hand operated and about 30 steam presses for lithography in the United States
• Transfer process


  A drawing or writing done in special ink on special paper could be transferred from the paper to the lithographic stone where it became the printing image
• The transfer process helped increase the popularity of lithography as a copying process because previously printed images could be transferred to the stone to be reproduced
• Direct rotary presses


  Presses that printed directly from the metal plate to the surface of the paper, but the image on the plate soon wore off due to the abrasive action
• Lithography lost ground to letterpress machines due to the flat bed design of its presses, which was a slow process
• Photolithography


  The act of making a lithographic printing plate by photographic means
• Alphonse Louis Poitevin invented photolithography in August 1855
• Photolithography made it impractical to coat the stone directly and expose it to light, leading to experiments with the transfer process and using metal plates instead of stones
• Process color printing


  The full color reproduction of a color original using only three colors of ink: yellow, magenta, and cyan
• James Le Blon first conceived process color printing in the late 1600s, and Louis Ducos du Hauron outlined the idea of reproducing objects in their natural colors by the superimposition of three photographically produced pictures in magenta, cyan, and yellow in 1868
• Halftone photography, photolithography, and process color printing were important steps in the history of lithography, but were limited by the flat bed litho stone press and the rotary direct press
• Offset press


  A press that removes the direct contact between the plate and the paper surface, preventing the image from wearing away quickly
• Lithography


  Printing using three colors of ink instead of three continuous tone photographically-produced pictures
• Lithography process


  1. Use three overlapping halftone images, one each in magenta, cyan, and yellow

  2. Adjust exposure time for each image so that no excess of any color would appear
• Halftone photography, photolithography, and process color printing were very important steps in the history of lithography, but were unable to be put to much practical use due to the limitation of the lithographic press
• Both the flat bed litho stone press and the rotary direct press had too many limitations, so lithography lay dormant waiting for new impetus
• Offset press


  Removes the direct contact between plate and paper by the addition of a rubber blanket surface
• Offset printing process


  Plate image is transferred to the rubber blanket which, in turn, transfers the image to the paper or other substrate
• The lithographic offset press had its origin in England


  About 1875
• Ira Rubel


  Paper manufacturer from Nutley, New Jersey who produced the first use of the offset process in the printing of paper
• Ira Rubel discovered the use of the offset press for paper printing


  About 1904 or 1905
• Charles Harris


  Designed an offset press around a rotary letterpress machine
• The offset lithographic press had six systems: feeder, feed board/register, dampening, inking, printing, and delivery
• The offset press allowed the photographic inventions of halftone photography, photolithography, and process color to become very popular within the lithographic field
• The offset press brought lithography from a relatively unimportant part of commercial printing into the number one spot in the industry
• Lithographic plates


  The quality of the plate determines how the image will print as well as the number of problems to be solved in order to maintain good print quality
• Evolution of lithographic plates


  1. Limestone plates

  2. Metal plates with image transferred from a master

  3. Bare metal plates coated with potassium bichromate and albumin, exposed, washed, and inked

  4. Pre-coated (pre-sensitized) aluminum plates developed by 3M in 1951

  5. Subtractive plates with no image developer needed

  6. Aqualith plates requiring only water to remove unexposed coating

  7. Waterless lithographic plates developed by Toray in the 1990s
• The major events in the history of lithography increased the popularity of the lithographic process, evidenced by the 3000% increase in the number of lithographic printing firms from 1900 to 1970