All printing process are concerned with two kinds of areas on the final output:
Image Area (printing areas)
Non-image Area (non-printing areas)
After the information has been prepared for production (the prepress step), each printing process has definitive means of separating the image from the non-image areas.
Conventional printing has four types of process:
Planographics, in which the printing and non-printing areas are on the same plane surface and the difference between them is maintained chemically or by physical properties, the examples are: offset lithography, collotype, and screenless printing.