What are the different Printing Processes?

What are the different Printing Processes?

  1. Offset Lithograph

  2. Digital Printing

  3. Large Format Printing

It’s a cloudy Sunday morning. After all the dilemmas of preparing artwork, choosing both a paper size and weight you finally have a chance to relax. This has been a long and arduous journey. But finally, you see the light at the end of the tunnel. To your knowledge everything has been decided, your magnum opus is in the capable hands of the printer.

An alert. You have another email. Panic sets in, however on opening it you see that it’s just a summary of your print job. Relief washes over you. The worst is over.

But what is this, the printer has asked you how would you like you job printed, ‘digital, litho, large format, inkjet?’ You’re confused, surely it’s just printed on a printer? What are all these mysterious choices to be made, and should they be feared or have reverence paid to them?

We hope these descriptions will help you understand what the hell they are on about:

Offset Lithography

Also known as offset printing or litho, offset lithography is a very popular method of mass-production printing. It involves printing plates, usually made from aluminium, which each hold an image of what needs to be printed. The image is put on the printing plates using a photomechanical or photochemical process during a stage of production known as prepress. One plate is made for each colour ink to be printed.

The plates are attached to cylinders on the printing press. Working on the principle that water and ink don’t mix the plate is rotated over damping rollers (water) and ink rollers (ink). The non image areas on the plate attracted the water and image areas of the plate attract ink. That inked image is subsequently transferred first from the plate to a rubber blanket and then to the printing surface, hence the term offset.

A print job that prints only in black ink requires only one plate. A print job that prints in red and black ink requires two plates. The more plates that are needed to print a job, the higher the price.

When coloured printing is required the coloured images are split in Cyan, Magenta, Yellow, and Black (CMYK). A set of four plates is need running on four separate cylinders in the printing press.

In some cases, there may be more than four plates. If a logo must appear in a certain Pantone colour, for example, or if a metallic ink is used in addition to full-colour images.

Offset printing has a high set up cost, prepress time, plates and making ready the press. But once the press is running it has a very low unit cost, making it the most cost effective solution for quanities of 500 or more.

Digital Print

Digital printing is a method that covers a variety of different techniques including inkjet printing and laser. In digital printing, images are sent directly to the printer using digital files. A RIP (Raster Image Processor) converts the digital image into a language the digital printer can understand. This eliminates the need for a printing plate and can save time and money (unless you’re printing in larger quantities).

Most production digital printers use laser technology, similar to a photocopier. The image that needs to be printed is formed by selectively applying a charge to a metal cylinder called a drum. The electrical charge is used to attract toner particles. These particles are transferred to the media that is being printed on. To make sure the toner is fixed properly, the substrate passes through a fuser that melts the toner into the medium.

Digital printing allows for quick turnaround and allows businesses to print on demand. It’s also great for small run jobs, requests can be made for as little as one print. If you choose digital printing for the right job, it can make for a very cost-effective soloution that still produces high quality prints.

Large Format Printing

As the name might suggest, large format printing exists to produce maximum print roll width. Perfect for traditional advertising mediums and businesses who are looking to make a huge impact on their customers, this printing method gives you with a much bigger area to work on, as opposed to the other methods such as digital printing.
Rather than printing onto individual sheets, large format printing uses rolls of prints that are fed incrementally to produce one large sheet. Large format printing is the best option for large print media such as building wraps, billboards, banners, and murals.

Most large format printer uses inkjet technology, small droplets of ink that are propelled from the nozzles of one or more print heads. Inkjet devices can print on a wide range of substrates such as paper, plastic, canvas or even doors and floor tiles.

There are numerous other technologies and new ones being introduced all the time for printing on a multitude of substrates.

https://en.wikipedia.org/wiki/Printing