Posted: January 30, 2019 • Posted in: Company News
Lithographic printing was invented in 1796 and is now the most popular form of printing in the world. Used for long-run print jobs, litho printing produces a high-quality print finish that becomes more cost-effective the more copies that are needed.
This guide aims to answer some of the most commonly asked questions about offset litho printing in London…
What is litho printing?
Litho printing, lithographic printing or lithography is a printing process which uses plates to transfer ink to paper.
Engraved using a photochemical, photomechanical or laser engraving process, these metallic plates each represent one of the 4 CMYK colours – Cyan, Magenta, Yellow and Key (black), which combine to make up the final image.
Water is then applied to the plate using a roller. This water will not stick to the etched area. Because of the oil in the inks, the ink applied by another roller only sticks to the print area.
This ink is then transferred to a further roller, which removes the water and transfers the ink to the paper or card stock. This process is then replicated for each of the other colours in the CMYK process. It’s also possible to add further plates to print special colours or effects, such as Pantone colours, or metallic inks.
Because the ink is not transferred directly from plate to card, this process is sometimes known as offset printing.
What is lithographic printing used for?
The litho printing process results in the sharpest possible print finish. This makes it especially suitable for:
Because of the cost involved in setting up the plates, litho printing is not suitable for short-run jobs. However, as volumes increase, the lower cost of ink makes litho printing more economical.
What are the differences between litho printing and digital printing?
Is litho printing better than digital printing?
It was traditionally accepted that the quality of litho printing is higher than the output of digital printers. However, with advances in technology, the differences in output are now so small that most people can’t tell the difference.
The process of adding ink to the page means documents with large areas of solid colour will look smoother. For exact Pantone colour matching, the process of mixing inks must be done by hand. Although close, a digital printer cannot exactly match Pantone colours.
Litho will also provide a more vibrant finish. As the ink soaks into the paper, rather than sitting on the surface, the paper type will have more of an effect. While digital printing almost always has a matt effect, the litho finish more accurately represents the type of paper it’s printed on, be that silk, matt or gloss.
What special finishes can you use with lithography?
Litho printers often have at least one spare printing unit which can be used for a “special” colour or a special seal, in addition to the four CMYK colours. As this colour can be bespoke to the project, it can be a colour matched Pantone.
Alternatively, metallic gold or silver (or other colour) ink may be used to add a touch of class to your design. One other idea may be to use a fluorescent colour, such as bright oranges or pinks.
A spare printing unit may also be used to apply a machine seal to the paper. Virtually invisible, this seal protects the ink and expediates drying times, resulting in faster turnarounds.
We’ve been printing in London for 40 years. Whether you’re looking for short-run digital printing or great looking lithographic print for your brochures or flyers we can help. Please do come and see us on Pall Mall or call us on (020) 7930 1976.