Critical Visual Differences Between Digital and Offset Print

By | March 27, 2012

I haven’t stirred the pot in awhile, so I thought I’d take a few swipes around the edges today. I’m currently updating my customer education primer, “Digital Printing: Transforming Document Management and Marketing” and would like input from Digital Nirvana readers on what you believe to be the most important visual differences between digital and offset printing.

Here’s what I wrote. What do you think?

Visual differences from offset

This might sound like a big “duh!” so why mention it? The issue of offset versus digital quality has dogged this marketplace for more than a decade, so it’s necessary to at least give it a nod. Yes, digital quality is not the same as offset. It’s close, but not identical.

For extremely high-end jobs, such as annual reports, the choice is almost always offset, regardless of run length or price, but few applications fall into this category. Even many commercial photo books are now being produced digitally. The output won’t be identical to high-end sheetfed, but there are digital technologies that get awfully close. Some practitioners claim that, in some cases, digital production quality is actually superior.

In terms of appearance, one of the most basic differences between digital and offset arises because most digital presses apply dry toner on top of the paper, while offset uses liquid ink that soaks into it. Thus, sheets printed with dry toner can have a slightly brighter, glossier appearance (unless the sheet is coated, in which case the coating masks any differences in gloss between the two). If you run your finger across the top of the sheet, you may feel a slightly unevenness that comes from the differing layers of toner. In the sheetfed market, HP Indigo presses are distinguished by their use of a liquid toner that soaks into the paper much like ink. This gives the prints a more offset-like appearance.

In the high-speed, high-resolution inkjet market, one of the issues is color saturation. More water in the inks means greater challenges with drying, especially with high percentages of ink coverage. In the lower resolution (lower ink coverage) transpromo market, this is not an issue. But in the textbook market, this is why we’re seeing these presses used more heavily for higher education than for the more graphics-heavy K–12 textbooks. The imaging technology of the high-speed, high resolution inkjet machines (as opposed to the lower resolution transpromo machines) is still being refined, but certainly, the issues of heavy ink coverage and dry time will be addressed over time.

There are other subtle differences between digital and offset, such as scattering of toner around the edges of text, but marketers—and consumers—are unlikely to notice them unless they know what they are looking for and are looking through a loupe.

Keep in mind, too, that “difference” doesn’t mean “bad.” There are those, even experts in the printing industry, who actually prefer the appearance of digital print for some applications.

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14 thoughts on “Critical Visual Differences Between Digital and Offset Print

  1. Charles

    Heidi,

    I think you got it about right, but there are 2 things worth remembering about the gloss difference between the paper and the toner:

    1.) Many new digital presses have a low gloss toner that looks pretty offset-like across many kinds of stock types, notably “silk” coated stocks. There are some differences noticeable on very glossy stocks where the toner is more matte than the sheet, and at the other end on a very corse uncoated sheet.

    2.) Indigo definitely mimics offset due to the toner sinking into the paper, but the downside is that it also changes color when you use different kinds of stocks. An uncoated stock is more absorbant than a glossy coated stock, and they will have different colors.

  2. Rick

    To Heidi’s 2nd point, the same affect is true for offset printing as well as digital. This is where color management becomes critical, especially for anyone offering both options. We are a G7 Master printer and can produce identical prints from the Indigo and from the Heidelberg. The biggest difference comes from the line screen each press is using, which gives the overall quality title to the Heidelberg. But if you put two pieces on the table, there is no visual difference with both presses calibrated to a common color standard.

  3. Rick

    Sorry, meant to say “to Charles 2nd point”. And to his first point, I absolutely agree.

  4. Gee Ranasinha

    The only people looking at print jobs with a loupe are print industry professionals. The great unwashed don’t care.

    Let me give you an example: There’s an audible difference between low-bitrate MP3 files and a CD. Do MP3 buyers care? Most see the convenience benefit (instant access, portability, etc.) to outweigh any perceived quality difference.

    For years, digital print was seen as a distant second to quality offset. Today the technology at least equals (some say surpasses) offset. As a result, any technical or subjective differences between digital and quality offset are largely immaterial.

    The vast majority aren’t refusing digital because the toner sits on the substrate in a different way. They don’t care. Buyers of print are choosing digital based upon criteria that only digital can address.

  5. Heidi Tolliver-Walker Post author

    I completely agree with Gee. That’s why the report is subtitled “. . . .Transforming Document Management and Marketing” and not something about technology. The focus is on salespeople, CSRs, and others who are selling or interacting with customers and need to have some understanding of technology as it relates to customer concerns, but the bulk of the PDF focuses on applications, case studies, and best practices. The point I’ve always made about digital production is how it impacts marketing strategy, because as you say, ultimately, that’s what hits the pocketbook and therefore what customers care about.

  6. Damian

    The final verdict will rest on shoulders of clients. If they cannot see a difference in quality, without a trained eye, then they will rely on the quoted cost.

  7. Kristian

    My daily business is solely walk up, I have numbers digital machines and offset. I find most of my customers like the convience of attaining 1-1000 digital prints as well as the cost. More so I am understanding the customer service standpoint that I can hand over a job of flyers, business cards, posters, etc within a few hours and the customer is very pleased. I think in my certain industry people are more concerned with speed, quality, and cost. So if I can print out a proof which will be the finished product and the customer is happy, then I have a customer that is not only happy, but will also spread the word of quickness and quality. And that is what I believe we are ALL trying to attain be it offset OR digital….

  8. Wayne

    After over thirty years in the book manufacturing industry, I know one of the most predictable publisher reactions occurs when opening their new carton of books, inhaling through their nose, eyes closed, broad smile.

  9. Mitch Maller

    Heidi:

    So yes there is a difference between offset and digital. At the end of the day if the printed piece achieves the result it was intended to do: convey a message, drive someone to make a purchase, cause someone to visit a website and so on, what is the difference? So in the “battle” of offset vs digital the real question is not if the printed piece is of the highest quality, which of course it should be. But the real question is “does the printed piece meet the goals of those who paid for it?”

  10. Bruce Pikas

    I am a print buyer and buy a large percentage of my requirements digitally printed primarily due to short lead times and relatively short runs, typically 500 or so. I would prefer offset output. The reason being that we use large format graphics, often having large areas of dark solid colors. No matter how the digital press is adjusted, banding occurs. Depending on the angle that light hits the graphic, it can be more or less obvious. To me this is a defect, but as Heidi says above “the printed piece meets the goals of those
    who ultimately pay for it”

  11. Ronald Boyum

    I buy printing from many sources and can specify digital or offset printing. Yes, there is still a difference between offset and digital. We have seen over the last 2 years with the increased resolution offered by most laser/toner machines that the banding has become less of an issue and a large soild area have less streaking. This has lead us to allow more work to be done digitally. There is still the more quality conscious customer that demands more accurate Pantone matches and and the smoother offset look. Of course there are still the economy advantage that offset has on long runs.

  12. Shahar Klinger

    Just a small note, regarding HP Indigo’s “ink” – it is a common misconception that the toner sinks into the paper as in offset printing. Actually it doesn’t. When the toner reaches the blanket, all the carrier liquid in it is evaporated, leaving a sort of polymer, which then gets transferred onto the paper. In other words, it is no longer liquid, and therefore can’t sink into anything. This is the reason you need to prime every substrate that is printed on a digital machine, otherwise there is no toner adhesion.

    I totally agree that the final verdict lies in the hand of the print buyer. If the product meets their quality standards, then the technology used to print it is irrelevant. I get a lot of printed junk mail, some of which I would be ashamed to sell were I the printer, but as Gee wrote, the vast majority doesn’t care.

  13. Commercial Printing

    Hi Heidi, nice post. All the points mentioned in the post are extremely informative and useful. I would like to discuss some general tips over the topic-
    – The offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film (called “”fountain solution””), keeping the non-printing areas ink-free. While, Digital printing do not need plates and all colors are printed simultaneously (not layered like offset) to produce a photo. Digital is less warm in colors than offset.
    – Also, Offset Printing uses full colour (CMYK), Special Colours (PMS) and varnish inks on plates, Digital printing on the other hand uses toner to print in full colour (CMYK) but not Special Colours (PMS).

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