Litho Printing Technology Explained
Litho printing is one of the most common high volume, commercial printing techniques. Often referred to as offset printing, it manufactures high quality images and can be used to print on a wide variety of different materials including paper, cloth, metal, leather and plastic. Modern litho printing presses use a computer to plate system to transfer the image to the printer.
The main advantages of litho printing are the quality and volume you are able to print. Litho printing technology means that the unit cost goes down the more you print, making them perfect for large print jobs.
How does it work?
A printing plate with the design you wish to print is dampened with water and coated with ink. The ink only sticks to the sections of the plate that do not have water on them. The image picks up ink from the rollers, while the section you don’t want to print on attracts a water film, staying ink free. The printing plate is fixed to a moveable roller and the image is transferred onto the material, which is fed under the roller.
Unlike some printing techniques, the paper or material you wish to print on does not come into direct contact with the plate. It is because the plates never actually touch the material itself that the printing technique is called ‘offset’.
There are two ways of printing using the litho process. The first is known as CMYK printing, the name refers to the four different ink colours used: cyan, magenta, yellow and black known as key in the printing industry. These four colours make it possible to print practically every colour of the spectrum. As the printing press is always filled with these four colours it makes it a very affordable printing option.
The second process is called spot colour printing; this is usually used when precise colour matches are needed for a print job. With the second process, inks are mixed specially using a guide and loaded into the press. It is the more labour intensive of the two but ideal if you require a specific colour shade.
As a result Litho printing is still a more cost-effective option compared to digital printing techniques. When looking for companies who do online printing, litho printing will most probably be the technique used.