Explaining Offset Printing

Very seldom do we think about the process needed to create that colorful magazine or fascinating brochure we routinely read.

Perhaps the reason I think about it is because I enjoy writing. To create a magazine, brochure, catalog, or any printed material requires a creative process. It is a group effort of writers and designers working together, which are then followed by printers, whose responsibility is to transform the creative designs of the writers and designers into works of art. Letterpress and screen-printing are only a few ways that ink is put into paper, yet offset printing is perhaps the most widely used processes by most print shops.

The process of offset involves the transferring of ink from an impression cylinder to the printed sheet. Years ago, lithographers used engraved images on flat stones. Today, instead of stones, images are transferred from a printing plate to a rubber blanket and finally to the paper. The principle is based on the simple fact that water and ink do not mix. The printing plate is covered with an ink receptive coating, then dampened by water rollers followed by ink rollers. The ink adheres on the imaged area only, while the water adheres to the non-image area. The image is then transferred to the blanket. The paper passes between the blanket and the cylinder, transferring the image to the paper.

When working in four-color process, offset printing is very good, especially if the job is fairly detailed with a lot of color or tonal ranges. Modern printing has increased significantly in quality and quantity because of offset printing.




 

Printing information index  | Terms for this site | Papers | Printing | Types

Printing Guides - Brochures - Business Cards - More Favorites