Printing has traditionally dominated the way in which graphic designers work: field such as packaging, exhibition design, and advertising are largely defined by the different printing processes associated with them. But the printing methods that dominated the major part of the twentieth century have seen rapid revolutions. During the 1960s, offset lithography took over from the labor-intensive letterpress printing, and within a decade became the most common form of reproduction. This major change was followed closely by computerized typesetting, which was finally absorbed into personal computer systems.