Printing Methods – Waterless Offset
Posted by admin at April 29th, 2016
There is another form of offset printing which is known as “Waterless Offset”. Waterless offset uses the concept of differential adhesion to keep image and non-image plate areas separate during printing. No fountain solution is used in this process.
The method used to achieve this type of printing is a silicone coating on the surface of the offset plate. During plate development silicone is removed from the image area of the plate. Silicone is not removed, however, form the non-image areas. The image areas with no silicone now sit slightly below the non-image silicone area forming very shallow “wells” to hold the ink. The ink is formulated to resist adhesion to the silicone but will deposit in the non-silicone shallow well areas.
Ink viscosity is important so several of the ink rollers must be cooled/heated to maintain a constant temperature which in turn will keep the viscosity constant.
Waterless printing has some advantages over conven-tional offset as colors are more vibrant and the printed image sharper; however, the overall cost is slightly higher. The plate being made with silicone scratch easily so most waterless printing today is done on sheetfed presses.
Category: Printing Methods