Offset printing is the process of applying ink to paper in a printing press.
Offset printing is a process to apply ink to paper with a printing press using plates where the image to be printed is reproduced. Standards facilitate communication between the printer, the ink manufacturer, the manufacturer of the printing plates, the customer and the agency preparing the material for the customer. A standard is a publicly accessible document, agreed in a standardization committee, which can be made binding by national or international agreements.
How offset printing works
The plates in the offset printing process, which are mounted on the rollers and used to transfer the ink to the paper, are typically steel or aluminum. Offset printing presses operate at high-speed, producing thousands of printed sheets per hour. The ink has to stick to the paper or rubber sheet which transfers the ink to the paper when it passes the plate, but not run in between. This requires a precise chemical composition of the ink -- including the color medium.
Colors in Offset Printing
In offset printing, each plate only applies one color. To print in more than one color, a series of plates apply ink to the paper, each producing a different color. Using primary colors in the ink, mixing them, and printing one color on top of the other creates different colors. Printers use a color standard as a benchmark to verify color is consistent from press run to press run.
Colors of Offset Printing Ink
When using the process printing colors of cyan, yellow and magenta to create different colors, it is important that one batch of ink does not vary in color from another. If they do, they will not produce the desired color when mixed or printed together. The production of offset printing ink is a very precise process, where the colors have to conform to exact standards.
Communicating Offset Printing Colors
The original that is the base for the printed copy sometimes comes from a different organization than the printing house. To make a precise match of the original with the final printed product, standard colors are used. This is particularly important in electronic communication, where colors may vary slightly between different types of computers and computer screens.
