Sorting Through Papers

How can you make sure your job runs flawlessly every time? One key is to ensure the paper you’re using is compatible with your production inkjet device. But print service providers are finding that’s sometimes easier said than done.

There's often confusion over available consumable options, stemming from the sheer number of products sold, so said Rick Williams, Cincinnati-based product development coordinator for Memphis-based International Paper. "There are a lot of manufacturers producing paper, but not all paper is developed to optimize high speed digital inkjet presses. With the many machines on the market, and more coming, it is important to understand that paper manufactures are working to make sure our products are keeping up with these new presses in order to optimize their performance."

For instance, understanding if the press  is positioned as pigment-based or die-based may vary the type of consumables one should utilize. "Everyone has markets they deal in, and when they look at buying one of these presses, which are fairly high-cost investments, they look at whether they have a market to justify the purchase. When they make the decision, the paper manufacturers need to come in, and work with them on the papers they offer to position them in the market and ensure the papers are meeting their needs," Williams said.

Williams has contacts with every inkjet press OEM, and works with them to test and qualify International Paper's digital paper lines. Paper manufacturers can also offer OEMs their expertise in developing presses, and provide their own customers with sample rolls to ensure their papers meet the needs of these printers.

Identified as inkjet

One of the most important keys is for print providers to ask the tough question: “Is this inkjet-approved paper for my high-speed inkjet machine?”

That’s the conviction of Ross Van Burkleo, digital sales manager for Neenah Paper in Austin. “You can’t just ask, ‘Is this inkjet paper?’” he said.

“In the paper world, we think of inkjet as desktop, small office-home office type use. That mentality has to change. Companies like ours are researching the inkjet market to say this has to be high-speed inkjet, distinguishing it from the small office-home office type use. What we thought in the past has got to change to what will be common in the future, which is high-speed inkjet.”

The problem, he added, is that different industries identify different papers as “five-star rated high-speed inkjet paper,” and mills have not agreed upon a specific nomenclature to describe high-speed inkjet compatibility in papers.

If the task is simply printing black-and-white copy, many substrates fit the bill, Van Burkleo said. “If you are, however, printing high-end vivid color reproduction on a high-speed inkjet press, sometimes a special primer is needed on the paper,” he added. “It just depends on the actual output. It all has with matching the paper substrate with the application being performed on press.”

Van Burkleo urges PSPs to research the paper mills’ inkjet and digital offerings, and what attributes of each paper the mills are promoting.

In addition, print providers should rely on good merchant distribution partners supplying the paper substrates. “These are the local salespeople who can help you navigate through these substrate choices,” he remarked.

One Size Doesn't Fit All

When examining paper, inkjet printing is particular in that it reacts differently than traditional and sheet-fed digital technologies, said Julie Loyer, in communication and sustainable development with Cascades Fine Papers Group in Saint-Jerome, Quebec. “A sheet that works very well on an offset press will most probably produce lower-quality results with an inkjet press,” she said.

“This is why Cascades has chosen to start its development process with a focus on what differentiates inkjet from the traditional presses. We are using a special treatment that is applied on the surface of the sheet. This allows the ink to stick to the surface of the sheet. It controls the absorption and ensures that colors remain vibrant. It also provides a great gamut and sharp results.”

Ink technologies, whether die or pigments, also perform differently on paper. While most papers specifically address one of those technologies, Cascades Enviro Jet works very well with both types, Loyer said.

This advance was made possible through the development work done in partnership with major inkjet press manufacturers. “The special surface also enabled Cascades to use 100 percent recycled fiber when making the sheet, while keeping all its important attributes,” she added. “This helped us to produce a very high-quality paper with one of the lowest environmental footprints.”

Controlling Quality

In high-speed inkjet printing, paper is the most important consumable, because ink is a given.

“With paper, you control quality,” said Susan Brunner, sustainability, branding and communications manager, uncoated fine paper, Europe and international, for Mondi in Vienna, Austria. “Non-optimized papers deliver poor quality. Optimized papers deliver good quality. It’s as simple as that.”

There exist different levels of optimized papers, and different optimizations for die and pigment ink, she adds, noting that Mondi’s fully-treated high-speed inkjet papers are optimized for both die and pigment ink at the same time. That means that printers do not have to consider the type of ink they are using when selecting paper for an HIS print product, she said.

As for color gamut, the question is not only how much color is printed, but which colors are printed. “Non-optimized papers offer a limited color gamut and very often particular colors are critical, in terms of logos and corporate identity,” she said. “These can only be achieved with optimized grades.”

Optimized grades also offer the opportunity to reduce the amount of ink required, by retaining the colorants on the paper surface, allowing the same color gamut to be achieved with 20 to 30 percent less ink output on a fully-optimized grade compared to a non-optimized grade. Fully-optimized grades from Mondi are made for fast absorption, meaning ink can be absorbed at high speeds of 200 meters and more in the printing process. Or when printing slower, the heat used for drying the paper can be reduced. Decreased power consumption is one benefit. Another is a reduction in problems in finishing, because papers that have been heated less for drying tend to suffer from fewer curling problems.

In respect to environmental performance, which also is a point of differentiation, Brunner reported all Mondi high-speed inkjet papers are FSC certified, elementary chlorine free or totally chlorine free, with both virgin and post-consumer recycled papers optionally offered CO2 neutral.         

Collaborating on Coatings

An example of the synergies resulting from close collaboration between printer makers and paper manufacturers is seen in the working relationship forged between HP and Appleton Coated, said Ann Whalen, vice president of marketing for Appleton Coated LLC in Combined Locks, WI.

“In 2008, when HP was looking for coated papers that worked well with their T Series inkjet printers, they came to us and we’ve been working with them since, developing coated papers designed specifically for the HP presses,” said Whalen, who reports Appleton Coated is the market leader for coated papers for production inkjet. “Several of the papers also work on the Kodak Prosper.”

The goal of the collaboration was to produce coated papers that could provide as close to offset printed quality as possible, but would work on inkjet machines and offer all the benefits of digital printing, like greatly reduced set-up time, big reductions in waste and the advantages of variable printing.

Coated papers and inkjet technology have some compatibility issues, resulting from the fact that ink is carried by a substantial amount of water that then needs to be pulled out, leaving the ink on the surface of the sheet, Whalen says. Yet coated paper is highly desired and essential in many projects in the worlds of both book publishing and direct mail.

One of the choices PSPs must face when using uncoated papers is whether to use an inkjet treated sheet or not, Whalen said.  “If they use an untreated sheet, on the HP press they use a bonding agent that goes on every place the ink will be applied. That works well for light coverage like text. But for applications with more color and heavier coverage, you (will)  get a better looking result, and it will be more economical, to use an uncoated treated sheet. A coated sheet is a sheet that has a coating on top; a treated sheet is an uncoated sheet with a treatment.”

For the HP T-series presses, she added, uncoated treated sheets utilize the HP ColorPRO treatment, and a number of manufacturers of uncoated papers, including Appleton Coated, are licensed to provide that treatment to the papers.

HP’s Perspective

Speaking of HP, Yale Goldis, the company’s San Diego-based worldwide manager, product marketing, inkjet high-speed production solutions, reported PSPs must take into account a number of factors in choosing consumables.

The first focuses on what is included in the charges. Ink, print heads, other click charges and how they are measured, as well as whether service is included in pricing, are some of the options, Goldis said. Also to be considered is whether other fluids or print head wipes are included in a per-page price.

“A second area is media,” he added. “What range of media can print on the device, and does it have to be specialized inkjet media, or is a wider range of media able to be printed on that device? I divide the world into a few types.

“There is coated media, and uncoated media. There is the offset version, which has both, and the inkjet version, which has both.”

HP offers the ColorPRO brand, which has specific inkjet technology in the coated and uncoated media that is optimized for printing with HP production inkjet devices. The company also offers the bonding agent cited by Whalen.

Unique for HP, it is a colorless liquid that prints underneath the colored ink, providing vibrant colors, low strike-through, and dark blacks, as well as a little feathering. The bonding agent interacts with the ink, fixing the ink on the paper. It allows more media independence, to permit a wider range of media to be used on the inkjet devices, and is digitally printed only where it is needed.

“The bonding agent will allow you to print on a wide range of standard uncoated media,” Goldis said.

In addition to HP’s ColorPRO coated and uncoated papers for inkjet, the company also offers non-ColorPRO branded coated and uncoated papers. “Our press can work on either kind of inkjet media,” Goldis said.

Goldis offers one final caution to PSPs. When comparing consumables, it’s best to “have a wide range of samples in front of you, as well as the ink you want, the media you want and the price associated with that sample, to help you make a good comparison,” he said.

HP’s New Media Certification Program

In mid-November 2013, HP announced its new Inkjet Web Press Media Certification Program for HP Inkjet Web Presses. The program is designed to help PSPs save time by quickly identifying a range of substrates compatible with HP high-speed production inkjet systems.

The Media Certification Program not only streamlines and simplifies choice points for PSPs, but also encourages paper manufacturers to develop and qualify a wide range of affordable media for HP Inkjet Web Presses.

The program incorporates several procedures for evaluating inkjet coated, offset coated, inkjet treated uncoated and offset uncoated papers.

Once they undergo initial screenings, substrates are given more thorough evaluations of performance within the press. Gamut, image quality, text quality, show through, durability, runability, and flatness are all tested. After certification of substrates, manufacturers of the papers receive a “Certified for HP Inkjet Web Press” badge that can be used in marketing and on packaging.

Aurelio Maruggi, vice president and general manager, Inkjet High-Speed Production Solutions for HP, reported: “Media versatility is one of the most common concerns of customers and prospects considering production inkjet equipment. The new media certification program builds on our overall media strategy, which also includes HP’s unique bonding agent for production of low-cost, uncoated offset papers and our collaboration with leading paper mills on the development of inkjet optimized papers.”