The short answer to the question is two. How it works, however, is a bit more of a detailed response.
If you’ve ever heard of the word lithography, you would be excused from thinking it had something to do with fancy writing, like calligraphy. In fact, very few people have a direct understanding that it really has to do with mass printing. In fact, even fewer people still understand how the process actually works, printing large amounts of duplicated text and images using rubber mats attached to metal plates. The entire industrial process was created decades ago, and essentially uses technology that was invented centuries earlier. Folks just became extremely good at creating efficient printing machines using the same idea better and better on paper output.
What are the Disadvantages of Offset Printing?
While offset printing has been used for numerous publications and paper printing, it doesn’t serve every situation well. In fact, when offset printing was primarily the only business in town, mainly businesses and newspapers were the primary customers that really made a regular use of offset printing. Average consumers either typed out a few copies themselves, used copy machines or hired a specialist to produce the cards or documents. However, with the advent of the computer and digital printing, that changed. More options became available for smaller print runs and short orders, which then opened up a whole new market in terms of commercial printing. Today, digital printing is a defined market all to itself, and it’s far better suited to certain uses than big runs from offset printing.
Cost, obviously, is the first big hurdle to the use of traditional offset printing. The price per output piece goes down with large runs in the thousands of copies. However, small runs don’t make sense. Part of the expense is the initial minimum base price; this helps the printer recover the cost of just running the machine in the first place. If an offset printer went lower, they would likely be losing money and eventually go out of business. So, there is a base price, the markup margin for overhead, and then the profit margin. Between all three small jobs get so expensive, they don’t make any sense being done with offset printing.
The next big challenge with small jobs tends to be their deadlines. They frequently expect a short turnaround. That doesn’t happen with offset printing because the metal plates that make it possible to produce a large volume of copies have to be set up and created first to make the print possible. As a result, offset printing tends to be saved for big jobs that are going to run for a longer schedule that accommodates the plate creation process.
Finally, offset printing doesn’t work as well when it comes to dealing with mistakes or errors. Because the runs are so big in offset printing jobs, if there does happen to be an error, the entire job may either have to be run anyway, and the client then just deals with it or the effort gets trashed, depending on how bad the error is. Many times, small issues are simply accepted and watched for the next time. However, a fatal error to a print run can be costly, and it literally could waste an entire job, usually at the customer’s expense. This is why test prints and prototypes are so critical to go over in offset printing before the main run is executed. If the issue is not caught in a test print, it’s usually too late after that point.
For the most part, the disadvantages of offset printing disappear as the job becomes bigger. The size and scale of production, as well as what is typically the revenue gained from the production pays for the efforts and cost with an added return as well. No surprise, newspapers, book publishers, magazine publishers and large print producers find offset printing the ideal path, even with some of its limitations versus the advantages of digital printing.
What is the Difference Between Offset Printing and Digital Printing?
As discussed earlier, the production methods and how the printing actually occurs makes up a large proportion of the difference between the two choices. Offset printing is far more mechanical with large machines, big rolls of paper or high production, and a heavy volume of output on each run. Digital printing focuses far more on high quality detail for smaller jobs. It works extremely well for highly customized jobs that have varying degrees of difference from one output to the next as well. A good example would be a limited run of art prints of the same image but in different variations to create a distinction between premium versions and far more common copies for lower pricing.
The setup time and creation of a print run is very different as well. With digital printing, much of the work is done in digital mode on a computer. With offset printing, the original layout might be done on a computer but the actual design and transfer to paper is done with printing machines, metal plates and rubber mats. All of that has to be fabricated and designed for the print job, which takes time and specialized effort. No surprise, the cost of running an offset printing job will make it prohibitive unless the output is big enough to make the effort worth the time.
Quality-wise, offset printing has a lower level of quality detail than digital printing. Where digital printing can deal with differences in nuanced colors, edging, detail and texture of images, offset printing will lose a lot of this quality, making very fine detail blurry, as if looking at it through a foggy pair of glasses. Because of this lack of detail, offset printing can only be done to a certain small size before the lettering and imagery become useless and just a smudge on the paper. Digital printing, however, does not have this problem, it can produce high quality imagery and fine lettering on all types of paper, and it’s frequently used for high-impact and customized publications.
During the digital printing process, unlike offset printing, toner is used for the actual ink applied to paper or medium. It is either sprayed on and dried quickly with a heating element, or it is burned onto the paper surface. A fast-moving jet nozzle does all of the hard work, which is a very different approach than a metal plate and rubber mat. Because of the speed of the nozzle running based on a computer program interpretation of the art or writing, the nozzle can produce a short run of prints very quickly. It might seem to take a few minutes overall, but given the amount of work involved, it would take a human many hours to produce the same by hand. Generally, print runs for digital printing can be as low as 10 to 20 and as high as a couple hundred items. After that, the cost starts becoming too much to make it worthwhile, and offset printing starts being looked at as the cost ranges of the two start to compete.
Digital printing is also unique and ideal when some kind of specialization or unique detail is needed for each individual print, such as a different serial number or symbol. The ability to make some kind of small variation that makes each item unique is very doable with digital printing as the nozzle simply handles the adjustment as part of a long run of instructions with slight changes from one print to the next. That’s not possible with high-speed big volume machinery utilizing mechanical plates.
What Does the Offset Printing Process Mean?
Lithography can be broken down into two main methods of offset printing technology, as noted at the beginning of this article. Sheet-fed paper is run through an assembly of machinery that prints the images onto the paper amazingly fast. The quality then depends on the imagery detail and the paper stock used.
The second category is web offset printing. This latter method also involves machinery, but these machines are far more associated with newspapers, being what people see when they remember movie glimpses of newspaper factories running the presses at high speed. The paper itself can be fed in stacks or in giant rolls, depending on the consumption level.
In comparison, the far more modern approach to printing tends to be digital printing. Originally, this was simply photocopying, but the technology has advanced significantly since those early days of image transfer burning on high-speed copy machines. Instead, the modern form utilizes extremely advanced printing computers that take in digital files and reproduce them exactly onto various paper stock and formats. Digital printing is ideal for short runs, small number projects and very high-end printing where cost is not an issue. For the most part, digital printing in the large amount of jobs tends to be associated with letterhead, business cards, marketing brochures and pamphlets, reports and similar.
The lithography process has been around for at least two centuries if not longer and probably dates back to the first newspapers being mass produced. Obviously, the form of offset printing used today was really made possible when high speed machinery could be run with electricity, but it was possible to do the same with combustion engine printing systems as well, just not efficiently. Again, the most common visual of offset printing is a newspaper factory spinning rolls of newspaper through its assemblies, creating sheet after sheet of newspaper pages at high speed. However, the actual print design creation is anything but speedy.
Many companies that expect they will be producing a heavy volume of printing with the same format tend to favor offset printing. Once the cost of the setup needed is addressed and absorbed in the overall project return, the cost per item starts to come down significantly because the machines used can produce so much in the same run. Digital printing can’t come close to the output possible with offset printing. And when the setup and job cost can be spread across so many units of output, the expense starts to shrink compared to the return of the overall job. This becomes really apparent when advertising pays for placement in runs of 5,000, 10,000 and more.
What Type of Ink is Used in Offset Printing?
The first step, as mentioned earlier, involves the design and fabrication of aluminum plates that actually carry the image of lettering and details that will be transferred to the paper. The plates themselves are monochrome, only handling one color at a time. However, multiple plates are used and, when combined in a printing process, they create a complete color picture on the paper. This approach involves variations of intensity of four main colors, ranging from black to cyan and magenta and yellow as well. They are better known in the industry as CYMK. Very modern offset printing can do more now with additional colors, but for many decades the four-color set was the standard.
Interestingly, offset printing has far greater latitude when it comes to printing on different types of medium versus just paper alone. It can be used on cardboard, cloth, wood, plastic sheet and anything that will fit through the machinery without a problem and take the ink applied. And modern offset printing has a wide range of color capabilities because it allows for color mixing to a great degree. So, where other forms of printing would have to obtain the specific color ink, offset printing simply uses the right percentages of certain colors to produce the right color mix instead. It’s far more efficient in terms of changing or addressing a wide range of color applications effectively.
Later versions of offset printing technology have expanded beyond the basic four-color set of CYMK, and some systems now create even more detailed mixtures from as many as 16 different base colors. However, the CYMK approach continues to be an industry benchmark because it is so reliable and so versatile for most high-volume commercial needs. Pantone, for example, offers an alternative approach which allows printers to use it with greater flexibility than being locked into just the primary mixtures of CYMK, but with that broader range comes a greater cost of materials and setup as well. When the majority of the industry is running on the high efficiency model of CYMK, it can be hard for a competing printer to make a niche running operations with higher costs of a bigger palette.
Which is Better Offset or Digital Printing?
While lots of folks want an easy answer that applies to every situation, the most professional of printers will all agree there isn’t one. The appropriate printing approach depends on a variety of factors that typically make one approach better than the other for that specific case at that time. While in many cases it is technically possible that both systems could produce the print desired, it’s neither practical nor functional. For example, why would anyone even consider using high volume machinery for marketing brochures? It would be extremely work intensive, costly, and then require even more manual work to size down the prints to individual pieces. The approach doesn’t make any sense in application, but it is technically doable.
On the other hand, if one wants to publish a book with a couple thousand copies, doing so with digital printing is possible but not recommended. In fact, offset printing could produce and finish books and ready them for market weeks and months sooner than what it would take using digital printing. The main reason is that offset printing provides big volume quickly, which is what would be needed for a large number of book releases. Again, however, it depends on the case. If the same book were to need a limited run premium edition with very detailed pages and quality, digital printing might be the better choice for that limited edition book. Interestingly, even in this regard, a number of publishers are disguising offset printing with the core of the book, and only running the outside wrap or inner binding leaves through digital printing for a unique look from one book to the next. Then both elements are combined in the finished product, creating the “premium” effect of a limited run.
On a quality level, page by page, the competition is high with a detailed offset printing job versus a digital printing one. That needs to be qualified, however; offset printing can range from very minimal detail as seen in newspapers, to very high output seen in glossy magazines. However, at a certain point, digital printing starts to surpass others because it provides more customization not possible on the offset side. Experts will pick up on these differences quickly, but the average person probably would not notice much of a variance.
For those who are cost-conscious and not expecting a significant cost recovery from the print job provided, especially in the case where the print output is going to be provided freely without payment, digital printing is probably going to be the better approach. It avoids the set-up costs that are inherent with the metal plate designs needed, and the volume runs tend to match what’s needed for special events, limited audience and smaller productions.
Offset printing should really be reserved for audience needs that are in the thousands and the print product will have either some kind of price payment or its extensive reach is going to return a significant revenue reaction, such as a wide-ranging marketing effort that pays well with a few successful responses for a call to action. In this regard, the numbers of possible reach are extensive, and the return can be hundreds to thousands of times over the cost of a single output piece.