Flexographic printing is similar to Offset Lithography and Rotogravure printing in the fact that it is a rotary printing method. It relies on rotating cylinders to apply the ink and feed the paper through the printing process. It is different from other rotary printing methods in the fact that it uses plastic or rubber relief plates on the printing cylinder in order to transfer the image to the stock, as opposed to rotogravure, where the plate is etched metal. The rubber plate makes the printing process very versatile which is why it is commonly used for packaging material ranging from toothpaste tubes, to crisp packets, to sheet metal that will go on to be made into cans etc. The process allows for all sorts of stocks like plastics, papers and metals to be printed on. It is a CMYK process meaning that the image passes through 4 separate rolls of cyan, magenta, yellow and key (black) to produce a full colour result. The inks that are used tend to be fast drying in order to facilitate the process. The process can be married with web printing so that a continuous roll runs through the printer. This is handy for long prints such as wrapping paper.
Like rotogravure printing, flexographic printing was developed in the late 19th century and grew in popularity. However, in the 1940s the process was cut down due to the Food and Drug Administration deeming the ink used in the process as unsuitable for food packaging, although it is only until recently (the past couple of decades), that the process has been developed and it has been rejuvenated by been one of the most popular commercial packaging printing processes again.
A Profile Diagram of the Printer Rolls
A Flexographic Rubber Printing Plate
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