Chapter 2
Basic Principles, History and Present of LithographyI will explain the basic principles of lithography for research and development.
Lithography is a kind of planography that was invented by Bavarian author Alois Senefelder in 1796. This printing technique uses chemical changes to create a printing plate and the printing process consists of the repulsion of oil and water.
After having drawn an image on the surface of the printing plate with the oil-based acid-resistant mediums, apply a weak acid solution of gum arabic in water. The surface of the blank space without the image is oxidized by arabic acid. The blank space is hydrophilic and the part of the image is lipophilic: consequently when a proper oil ink is painted on the wet plate with a roller, the ink sticks only to the part of the image and the blank space remains clean with the water.
Gum arabic is an important material in lithography.
Gum arabic is a natural gum made of hardened sap taken from Acacia senegal and Acacia seyal. The main component of gum arabic is polysaccharide and it is a mixture of arabinogalactan (75-94%), arabinogalactan-proteins (5-20%) and glycoprotein (1-5%).
Arabinogalactan is soluble dietary fiber of quality polysaccharide which is a combination of monosaccharide arabinose and galactose. Also it is proteoglycan combined with a small protein. Arabinogalactan includes arabic acid [C5H10O5/C5H10O6] and it is hydrolyzed to arabinose and galactose.
Gum arabic contains dietary fiber which is not resolved by the mammal's digestive enzyme, including human. The aqueous solution of gum arabic is low viscous and it has strong emulsion stability and protective colloidally. It is used for food additives (thickener) in confectionery, ice cream and the like, also permitted widely using for medicines, cosmetics and daily goods.
In history of lithography, zinc plate had been used for limestone because the limestone is expensive, heavy and hard for handling. At present, aluminum plate is used instead of zinc plate: it is lighter than zinc plate and has high durability for printing.
Getting the zinc plate in Japan will be difficult by discontinuation of production from information what I have read on some Japanese Website which concerns printmaking. Also the number of Japanese makers of aluminum plate is decreasing in recent years. Moreover, the limestone of good quality for lithograph is not mined in Japan, so it is very expensive.
This is a reason why Japanese author Professor Ozaku developed plywoodgraphy that I have been researching. A plywood board is used for printing plate instead of stone or metal plate. It is cheap, light and easy for handling.
Finding new material and technique will be very important for the future in the same way that the material of printing plate has changed in history of lithography. Now, we may easily order almost all the item on the internet but it still needs time and cost of transportation and it is impossible to pick it up and look at the items actually. It is advisable that the materials for art are close and low price and the technique should be practicable in restricted environment.