The Web Printing Press
- Web printing is a rotary process, which utilizes roll paper rather than large, or small, "parent" sheets of paper which are pulled through one at a time. The rolls shoot through the web printing presses at very high speeds, with the newest versions running so fast it is mind numbing. Sometimes, should you be at a run check, you will see the pressman actually running between stations on these ultra high speed machines, making adjustments. This is because on these machines the paper consumption is so fast, that any errors cause great waste of paper. Paper is usually about half the cost of the job, so waste is crucial.
- There are two basic types of the web printing presses:
The Heat-set and Cold-set. The main difference is that the Heat-set web has heaters which dry the ink, thus allowing it to run coated stocks (gloss book, dull book, etc.) The Cold-set webs can only run offset-un coated stocks and newsprint. The secondary consideration between using a Heat-set or a Cold-set web is the line-screen. The Heat-set webs tend to be newer and therefore having a higher line-screen (133-175) and the Cold-set, having anywhere from 85-150 line-screen, with larger dots and less detail.
The next difference in the web style is size. Here, once again, size matters. The smallest rotary machine is the label web and these are only several inches wide. Forms presses and the "Didde" is the next step up as both generally run a 4 page configuration. These are also referred to as "quarter webs". Then there is the "Half Web ", which somehow manages to not only run the 1/2 form of the 8 page signature, but also is built to run a 12 page signature. This then brings us to the "Full Web", which is built to run a 16 page signature, as well as the newer full webs that can run "double sixteen's", thereby running 32 page signatures.
- May our printing press company be of service to you? We welcome hearing from you.