|
The Difference Between Screen and Offset Printing
The Chinese developed screen or silk screen printing during the Song Dynasty, somewhere between 960 and 1279 AD. The art form moved across Asia where it was combined with block printing and hand painting. The process was introduced to Western Europe in the late 1700s. Samuel Simon patented silk screening in England in 1907. This was the popular European method of making elaborate wall paper. Images were screened onto fine fabrics such as silk, linen and other expensive textiles.
Screen printing equipment includes a woven screen mesh. The mesh was originally made from human hair or silk. Now however, the mesh is constructed from steel, nylon or polyester. An impermeable medium is applied to the mesh to coat it and provide a negative image of a specific design. Ink is then applied evenly to the screen. A squeegee or roller is brought across the screen which forces the ink through the open areas onto the printing surface below.
The image on the screen mesh can be removed through a special cleaning process and a new image applied. Screen printing uses colors one at a time, to produce a variety of images on different mediums such as paper, fabric, glass, plastics, or wood. Images can be mass produced in this manner.
In contrast, offset printing occurred when ink was applied to a limestone surface, then transferred or offset to a cardboard covered surface and then applied to the surface where the image was to be printed. The cardboard surface was later changed to a rubber blanket.
In 1875, Robert Barkley of England combined this technique with Richard March Hoe’s 1843 invention, the rotary press, to create the first offset printing press. Today, water and ink rollers transfer the ink mixture to a plate cylinder, which in turn transfers the ink to the offset rubber cylinder and onto the printing surface.
Most notably used for printing newspapers, these offset presses are also ideal for mass production. The cylinders do wear out in time or experience image distortion due to the chemicals used in printing and cleaning.
Screen presses can easily be bought commercially or made at home, allowing for many to start screen printing hobbies or businesses. Inks and cleaning chemicals can be purchased online or where printing supplies are sold. Rarely does an individual own and operate an offset press. They are larger, cumbersome, more expensive to acquire and more expensive to maintain.
| |
