By Cassandra Balentine
In the print process, the proof is part of the contract between print provider and client. Therefore, it is essential that it is a controlled and accurate presentation of what to come. For digital and/or hybrid printing environments, inkjet proofing looks a little different than traditional processes.
“In traditional print environments, the presses need to be completely setup with inks etc., run, and then changed over to the next run or completely cleaned up. This is a resource—labor, time, and materials—consuming process and ultimately an expensive way to produce a proof, especially if there are going to be multiple iterations,” shares Tom Wittenberg, large format industry relations and events, HP, Inc. “From experience, we would try to avoid this with soft proofing through as many iterations as possible and then go to press to produce the final. With digital printing, it is a matter of creating the file, loading it into the RIP, loading the media, and running the job. This is much quicker and certainly less expensive versus the analog printing route. No expensive setup costs, media usage to bring color into line, etc.,” he explains.
The inkjet proofing process must be flexible to suit a variety of customer and packaging needs, in addition the requirements of proofing digital offset are different than commercial offset print environments. “RIP systems need to allow for imaging different dot patterns like contone or halftone dots to better suit customer expectations,” says says Marc Aguilera, product manager, Professional Imaging, Epson. “It’s no longer necessary to produce analog proofs since most commercial print environments are CTP where a digital halftone dot can be used.”
Jay Roberts, product manager, UV printers, Roland DGA Corp., believes digital and offset printing environments are very similar. “In traditional print environments, proofing has migrated to 24- or 44-inch, water-based inkjet printers. The quality of these printers is very good and the color gamut is extremely wide, which means that traditional offset printers can easily proof its output to these proofers—minus the halftone dot,” he explains. “In comparison, the new hybrid proofing systems use solvent or UV printers. The quality is also good, and the color gamut is wide enough to proof to the color output desired. The output—typically GRACol in North America—can easily be met by both solvent and UV printers. The advantage the hybrid printers have, which differs from traditional proofing output, is that they can proof to the actual substrate desired by the client,” he adds. This is an advantage for the customer because they can see the real color on the actual material, providing a realistic proof.
When it comes to advancements in digital inkjet printing technology, a lot can change in a limited amount of time.
Over the past few years, printer manufacturers have widened the gamut, bringing in other colors to help achieve spot color accuracy and increase speed. Further, Wittenberg says the introduction of the onboard spectrophotometer has significantly increased the ability to hit colors as needed.
Aguilera agrees, adding that RIP systems have also evolved their screening algorithms, color management calibration, verification, and profiling capabilities. “In combination, these evolutions have led to enhanced, faster, printers for the proofing environment such as the new Epson SureColor P7570 and SureColor P9570, which leverage UltraChrome Pro12 Ink with Violet to produce color with up to 99 percent coverage of the Pantone Formula Guide solid-coated standard, ideal for proofing environments. The SureColor P7570 and P9570 are also compatible with spectroproofers designed jointly with X-Rite to provide automated color measurement when driven by a supporting third-party workflow RIP to further automate the proofing process.”
UV proofing has become widely used and accepted within the industry. Roberts credits this to the ability to measure the color of the proof and compare it to the standard adopted by the major RIP manufacturers. “This advantage, combined with the ability to print on the desired stock, has popularized UV or hybrid proofing. The growth of proofing to actual media has grown significantly over the last five years.”
In addition to the mechanical elements of the print engine, ink plays an essential role in the hard proofing process.
Ideal for proofing, Epson SureColor P-Series printers use aqueous pigment ink sets. Aguilera says pigment inks are selected for their lightfastness, durability, and wide gamut characteristics. Epson aqueous ink sets—UltraChrome Pro12, and UltraChrome HDX inks—are used in proofing environments because the extended color gamut can achieve up to 99 percent of the Pantone Solid Coated library of colors.
Wittenberg believes HP Latex Inks are used for proofing because they have been a top-selling brand for production and when not in use, can be used for proofing.
Roberts stresses that UV inks are gaining popularity faster than any other ink set outside of the traditional proofing market. “The ability to proof to the exact materials, whether that be white or colored stock, has increased overall demand for these inks. Making UV inks even more popular is that they can proof not only with white ink, but with gloss ink as well. These combined advantages have increased the demand and relevance of UV inks within the market.”
He points out that Roland DGA’s UV inkjets can print onto hundreds of types of materials—in fact, they can print on just about anything. “Combined with a good RIP and strong color management, these printers can produce extremely accurate ‘live proofs.’ By live proofs, I mean proofs on the actual substrate that will be used to create the finished product, which allows for the most realistic representation.”
“For the most part, one is limited by the media that they printer can run,” says Wittenberg. The greater the versatility of the printer, the greater the breadth of media and media types that can be utilized for proofs. “This is also a big advantage for customers of HP Latex Printers due to the fact that there are over 600 media options approved to run through the printer. In addition, HP does have its own brand of media designed specifically with the HP Latex Technology in mind.”
Aguilera feels proofing media is critical to the success of simulating a target color space and media white point. Epson offers a full line of proofing media including Production, Premium, and SWOP3.
“There are multiple media manufacturers within the industry, and Roland DGA offers many different types of media as well. The key to the hybrid proofing environment is that UV printers can print directly onto just about any stock. That’s the real value. Unlike solvent or aqueous printers and inks, the UV ink cures on top of the substrate,” shares Roberts.
For proper proofing, the RIP paired with an inkjet printer must be top-notch. This piece is essential to the total inkjet proofing process.
In addition to managing color output, RIPs are also capable of correcting the output if needed and monitoring for color consistency. “These days, proofing begins by using a spectrophotometer to scan the color for accuracy, followed by correcting the color output using an iterative process, and then monitoring the color consistency throughout the entire print run. RIPs with these functions allow the print operator to show or prove color accuracy and color consistency,” notes Roberts.
Wittenberg explains that the RIP supports spot color or custom color matching. “Each RIP has its own way of managing this,” he offers.
Hard Versus Soft
Soft proofing is often utilized for certain projects or points within the approval process. There is a place for both in digital and hybrid print environments.
“From experience, customers have really liked the hard proof,” offers Wittenberg. It provides the opportunity to see colors and images on the selected media. “It’s the real deal. Soft proofing is good for giving you a good idea of what the final image will look like, but it doesn’t have the final look and feel of the product.”
Aguilera agrees, noting that a hard proof is tangible and can simulate contone or halftone ink dots as well as predict color, whereas a soft proof is pixel based and can therefore only proof for overall color appearance.
Roberts says soft proofing is valuable because the client can be anywhere in the world and see a proof. “Hard proofing—especially hard proofing onto the actual stock—makes sense when the materials being proofed are not traditional stocks. A lot of packaging and prototyping can be proofed to the unique substrates, which allows for real-world proofing as opposed to content/color balance proofing.”
Many feature sets make wide format inkjet printers well suited for proofing in digital or hybrid commercial print environments.
When working with customers, Wittenberg says the biggest single advantage is that you can tell the customer that the proof came directly from the printer that will make the final product. “What you see is what you will get. The second key feature is that you can proof with your production equipment easily and cost effectively with a quick turnaround.
It beats analog proofing hands down. Finally, you can work with the color in prepress or the RIP to get the exact color you need without a lot of trial and error.”
Epson’s line of SureColor P-Series printers includes its PrecisionCore TFP printheads, which are designed to yield unmatched color consistency, reliability, and durability to last the life of the printer. “These characteristics are important to the success of digital proofing. The UltraChrome Pro and HDX ink sets in our proofing products are also ideal due to their wide gamut, capable of simulating 99 percent of PANTONE solid coated colors,” offers Aguilera.
The Roland DGA IU-1000F is ideal for digital proofing—and production printing—because of its diverse ink configuration. The IU-1000F has CMYK, White, Gloss, and Primer inks—an ink set that allows for expanded material compatibility. Being able to print onto black substrates with white ink under the print makes the end product ‘pop’ with color. Additionally, the use of gloss ink adds dimension and focus to many point of purchase prints, explains Roberts.
Further, the Roland DGA TrueVIS VG2 series inkjets—Roland DGA’s newest eco-solvent printer/cutters—feature new inks that expand the color gamut significantly for vibrant output and color-accurate proofs. He points out that with three different configurations in CMYK, plus additional Light Cyan, Light Magenta, Light Black, White, Orange, or new Green inks, VG2 users have more color freedom and control than ever before. The addition of Green or Orange ink also means that you can consistently reproduce specific brand colors for clients and customers.
While these systems can be used as proofing devices, it isn’t uncommon for them to have other roles.
“I rarely see printers just setup for proofing,” says Wittenberg. “Remember, these printers are designed for manufacturing product. So most customers use them this way and fill in with proofing as needed. Where you might see one as a proofer is where there are a large number of small run jobs—small sign shops—where there will be a lot of proofing. If the business has multiple units, each one can be used as a proofer, as needed, if others are being used for production at the time.”
Aguilera says the Epson SureColor P5000, SureColor P7000, and SureColor P9000 Commercial Editions are generally purchased for graphic design and proofing applications but can also be used for other applications like photo printing, signage, posters, and indoor multi-use graphics. The SureColor P7570 and SureColor P9570 are very versatile and can be used in proofing, photo fine art, and multi-use graphic applications. “Our SureColor P-series printers are excellent for poster printer applications and are generally installed as multiple use products.”
Roberts says Roland DGA’s printers are not generally purchased just for proofing. “We do have a great proofing and RIP partnership with ORIS ColorTuner—for our VG2 printer line, but typically our printers are purchased to do both production printing and proofing.” He finds that most customers see the value of its printers being able to produce hundreds of applications, rather than focusing solely on proofing. These applications include vehicle graphics, backlit displays, decals, wall graphics, trade show displays, posters, point of purchase graphics, signs and banners, floor graphics, and outdoor signage. “Versatility is one of the key qualities that make our printers so popular with sign shops and graphic display companies. They’re able to capture more business because Roland DG printers allow them to significantly widen the scope of their product offerings.”
The Hard Truth
Inkjet proofing systems are utilized to give clients an accurate representation of what will be reproduced in a final run, along with the print engine itself, RIPs, media, and ink all play an important role in the process.
In digital and hybrid printing environments the contract proof remains an essential part of the equation for many print jobs, although soft proofing is also an acceptable option depending on the circumstance. dps
Oct2020, DPS Magazine