Writing With A Stone

Although the lithography process gets it name from Greek words for stone, and write, it wasn't a Greek process. Lithography was actually invented in 1796 and was called lithography because ink was applied to an etched stone and "pressed" off the stone onto paper or other materials. 


The process of transferring ink from one surface (like a stone) to another (like paper) is called offsetting. This is where the term "offset printing" comes from. 


Today lithographers/offset printers transfer ink to paper from photopolymer images on aluminum plates (they are a lot lighter than stones).


If you want to know a lot more about lithography, here is a link to the Wikipedia article.


Back to Offset Printing at ULitho



DIGITAL PRINTING

Toner based digital printing also uses an offset process. It begins with precise electrostatic charge drawn onto a drum with a laser. The charge is used to organize (attract) a dry powder called "toner" onto the drum. 


The toner is then transferred to paper which has been given a different electric charge that will attract the toner away from the drum. 


Finally, the toner is "fused" to the paper using intense heat and pressure.