Offset printing, often referred to as offset lithography, is a method of printing in which images are transferred, or offset, from metal plates to rollers or rubber blankets and finally to print media. Offset printing is ideal for high-quality mass-production printing at a reasonable cost. For a person interested in printing processes, here is an introduction to offset printing.

How Offset Printing Works
The offset printing process is relatively simple. During the process, ink rollers apply ink to the image area of a plate, while the non-image area holds water to keep that area ink-free. Each plate transfers an image to a rubber blanket, which then transfers the image to the printing surface. Throughout the process, the plate does not touch the printing surface; hence the name "offset." The printing surface then passes through an oven to dry. After the printing surface is dry, a set of rollers runs chilled water over the surface to set the ink and avoid smudging.

Types
There are two basic types of offset printing: sheet-fed and web-fed. Sheet-fed printing refers to a printing process in which each piece of paper travels through the press individually, a printing method ideal for small to medium volume printing jobs. Web-fed offset printing refers to a printing process in which a continuous sheet of paper travels through a larger, faster press at one time. Web-fed offset printing is ideal for large volume print jobs.

Applications
Offset printing is useful for many different printing applications that we encounter daily. Newspapers, magazines and books are some of the most visible examples of offset printing that people use and handle on a daily basis. Other applications of offset printing include legal documents, financial forms, greeting cards, marketing and advertisement materials and educational materials.

Advantages
Offset printing provides several advantages over other types of printing processes. One of the most beneficial advantages of offset printing is the high-quality images. Another advantage is the investment factor. While an offset printing setup is often costly, the unit price will typically decrease as the quantity increases. Offset printing is also useful for small- to high-volume printing jobs on various printing surfaces, such as cloth, leather, paper, wood, plastic and rough paper. Other advantages of offset printing include cost-effectiveness in high quality printing jobs and productivity.