The Truth on Offset Printing- Read Before You Print!

by Arthur Piccio on 03/02/2011

by Arthur Piccio  |  March 2, 2011  |  Print Tips

Anyone who finds themselves in need of a printing service will often come across the idea of offset printing. Though the basic technology behind this printing method has been around since 1875, few people actually understand its fundamental processes.


40 inch Mistubishi Offset press

With digital printing now a much talked-about technology responsible for a small but ever-increasing share of the trillions of pages of material printed each year, confusion over offset printing as a viable method today seems unavoidable. This FAQ will explain the principles behind offset printing technology and try to dispel some misconceptions of the technology in relation to digital printing.

Offset Printing FAQ



How does offset printing work?
-The process relies on the fact that water and certain inks do not mix. Text and images are first set on plates through a variety of methods, most commonly through a chemical process similar to film developing. Next water and inks are alternately applied on these plates, with ink adhering on the image areas and water on everything else. The images on the plate are then rolled over or covered by a rubber sheet, called a “blanket”, and from the blanket, the image is then transferred to the paper stock. The process is then repeated separately for different colors. Colors are applied as microscopic dots, blended in different proportions so that the human eye interprets them as different shades and hues. At no point in time does the plate transfer ink directly onto the paper, hence the term “offset”. This diagram gives us some idea of how the process works:



There are thousands of different variations on this one concept. So long as the ink transfers onto a blanket and then onto paper, the process would fall under the umbrella definition of offset printing.


Is offset printing an obsolete technology?
-Though offset printing has been around for a while, it’s definitely still a viable technology, with upwards of over 90% of all the printed material in the world being produced through this method. Modern offset printers are much more efficient and are almost nothing like the ones available at the turn of the 20th century, though the basic principles remain unchanged.


I read somewhere that offset printing is cheaper than digital printing, but then someone told me that this isn’t exactly true. What’s the real score?
-The truth is a little more complicated. Remember that over 90% of the world’s printing is done with offset processes, and that’s no accident. Generally speaking, offset printing is several orders of magnitude cheaper than digital printing, per piece- provided we are talking about a somewhat large printing run. The actual economics may differ depending on the machines, stock, costs of labor, and numerous other variables, but generally speaking the most expensive part of the offset printing process is not the actual printing but setting up the plates.

Setting up plates, even when aided by computers, can be a tedious, time-consuming business. If you only have a short printing run, you would not be able to extract the maximum value for the cost of setting up these printing plates. A properly set-up aluminum plate can be good for runs of several million standard magazine page sized prints. Printing runs of just a few hundred may actually be more expensive than printing digitally. Digital printers also do not need plates and can print files directly, cutting down on the time needed for set-up.

At the risk over over-generalization, shorter runs are almost always cheaper on digital, and larger runs are almost certainly cheaper with offset printers. The printing run size at which offset printing becomes cheaper is totally dependent on the compared offset and digital printer models, and other related cost variables.


 

 

Close up of printing plate, ink roller, and rubber blanket

I heard digital printing is better. Is this true?
-It all depends on what you mean by “better”. No single tech is better than the other. As discussed earlier, digital and offset technologies each have the economic advantage depending on the size of the printing run.

When it comes to print quality, the offset process generally produces more consistent prints, provided the printers are run by experienced personnel. Digital printers tend to produce prints that are markedly different at the beginning and end of a print run. This is often due to the ink properties changing due to overheating nozzles or components of the ink settling overtime, among several other factors. This is now much less of a concern thanks to improving technology. For very short print runs though, digital printers today also produce very consistent prints.


A Canon imagePRESS C7000VP Digital Printer

Digital printers do not need plates, and as such they are much faster to set-up than an offset printer. Most printing jobs requiring very fast turnaround times generally use digital printing technology.

The decision to use offset or digital all boils down to just what you need at the time.


Does using an offset printer mean it’s more difficult to print files on my computer?
-No. Computers are used in conjunction with offset printers all the time, mostly when it comes to setting up printing plates. Setting up the printing plates does require time though. Is offset printing harder? With an experienced printing service, no. Does it take more time compared to digital printing? Generally, yes.


What’s this CMYK offset printing thing I keep reading about? Is it better than RGB?
-First, an overview of what these acronyms actually stand for. CMYK stands for Cyan, Magenta, Yellow, and Key Color Black. RGB stands for Red, Green, Blue. They are both color models that work by combining the color components in various amounts amounts in order to obtain desired hues.

RGB is the most used color model for monitors and other electronic displays. Chances are you are reading this through a display that utilizes RGB. CMYK on the other hand, is more commonly used in all kinds of printing processes, including offset and digital printing. The difference is electronic displays project and mix different colors of light, while printers blend pigments, on the (normally white) paper itself- absorbing light. Because the processes are so different, they cannot be totally directly compared.


Image courtesy of Av Empire

The challenges involved are different, and while RGB can reproduce more colors in the visible spectrum, CMYK is much easier to print technically and the separate black ink cartridge makes this color model much more economical, since colors do not need to be mixed so often. Also, RGB and CMY (without black) by themselves cannot achieve very deep blacks on print. Text also typically requires a lot of black ink, making CMYK a much more appealing color model for printers.

It is important to verify the color process your printer will be using, as files in RGB will need to be converted to CMYK for processing on most colored offset printers.

If you need to learn more about offset printing or about any of our products and services, please call us at 1-888-888-4211, or contact our chat support team through our home page.

This post was written by

Arthur Piccio is UPrinting.com's Small Business and Public Relations Coordinator.

Leave a Comment

20 comments

Daniel March 2, 2011 at 10:59 pm

Nice article to read !

Arthur March 2, 2011 at 11:09 pm

Thanks Daniel! Glad you liked it. :)

WizKid March 2, 2011 at 11:51 pm

Very nice article. Takes me back a few years when I worked for a local print shop who did almost everything using offset printing. That was probably one of the most tedious, time consuming jobs I’ve ever done. The sheer time it took to develope the film to make the plate & get it aligned was at times just not worth it. I never understood how the place stayed in business, cause in a small town & most runs only being in the 200-2000 range, seems like more $ was spent paying employees than was made off of the print jobs. Offset printing is definitely a craft & I have much respect for anyone who does this for a living!
Thanks again for the article, this will come in handy next time I need to explain the differences in printing :)

Arthur March 3, 2011 at 12:07 am

You’re welcome Eric! Prepping the plates can be tough. I don’t know how the guys back on the production floor manage to do it day-in and day-out either! :)

Janine March 8, 2011 at 6:18 am

Nice article we were just discussing our options for printing this year’s programs. I know offset printing charges by the color, does digital printing do that as well? Is a run of 1500 books, two colors considered big enough for offset printing? It’s 14 pages printed front and back, one of which is a heavier cover stock.

Arthur March 8, 2011 at 9:58 pm

Hi, Janine! Some printing companies do charge by the color, but we don’t. Whether or not they charge per color on digital printing services depends on their business model. 1,500 books would most likely be run on offset printers. Get in touch with our chat support line at our homepage or call 1-888-888-4211 if you need a more detailed discussion of your order.

Gareth March 8, 2011 at 7:19 am

You’re spot on about the quality difference between digital printing and offset printing lessening

QIS Print NYC March 8, 2011 at 9:29 pm

Excellent article – agree as well about the diminishing difference in offset and digital

Lalee March 9, 2011 at 10:59 am

nice!!!

Lalee March 9, 2011 at 11:00 am

Great article!!! understandable

Arthur March 9, 2011 at 4:06 pm

Thanks Lalee!

Sherry March 18, 2011 at 11:15 pm

Very informative. Now I know the differences between the 2! Thank you for sharing :)

Arthur March 21, 2011 at 6:49 pm

You’re welcome, Sherry :)

inspirationfeed April 30, 2011 at 10:30 pm

Great tips, and great article! Keep up the great work Uprinting!

Michael Wittmeyer September 26, 2011 at 11:05 am

Great article! If anyone would like a more visual look at the offset printing process, check out this infographic: http://www.businesscards.org/blog/how-commercial-printers-make-business-cards-infographic/1694/

arif December 7, 2011 at 8:49 am

sometime colors handling is much of a hassle in offset printing

The Offset Print Pro December 17, 2011 at 8:22 pm

Nice explanation. Good pictures. Good balanced explanation on the difference of offset printing with digital.

Patty February 14, 2012 at 2:35 am

Back in the day when everything was printed on offset machines designers had to understand the technology. Now they think their job is only to prepare files to look good on screen. They know nothing of dot-gain, press-gain and influence of stock weight on printing process. Sometimes printers even get a text which should be printed in B&W in CMYK…

maureen April 30, 2012 at 12:56 am

great article! Post more pls :)