First and foremost, in spite of some negative experiences in the past, inkjet printers are a viable option for contract proofing. In fact, it’s estimated that in less than five years as much as 90% of proofing will be done on inkjets.
The biggest selling points for inkjet proofs are the costs, faster turnarounds, fewer size limitations, the ability to match a larger number of printing variables and additional revenue streams through printing posters and short-run, wide-format graphics.
Choosing an inkjet proofing system can be challenging because there are a variety of vendors and combinations of RIPs, media, ink and printers. Do you want a turnkey package or will you build it yourself? A turnkey option takes the guesswork out of the equation but it will cost you more. Some of the options in the turnkey arena are: CGS’s ORIS ColourTuner, GMG’s ColourProof, Fuji’s (Enovation) Proofing Packages, Creo’s Integris & Veris, Dupont B2 and the Agfa Sherpa. Each of these options are complete inkjet proofing setups, offering very high-quality proofing.
It is crucial that a qualified technician install, calibrate and profile the proofer for your shop. It is also advantageous to profile your press as well. When considering a digital proofing system, you need to be confident with the individual doing the calibration and profiling, as this is the most significant variable in getting accurate colour reproduction from any proofing device.
Easier Colour Management, Better Inks and Media
Colour management and rip software are getting easier to use. This is evident in CGS’s, soon to be released, 5.1 ColorTuner, which will offer a wizard-like approach to calibrating and profiling the printer. Other software vendors like EFI, ProofMaster and BlackMagic have also reduced the complexity of their software.
The quality of proofing medias and inks has also greatly improved. One product is Epson’s UltraChrome ink, a diluted pigmented ink. Previous pigmented ink that was great for archival usage but appalling for saturation (low gamut). Epson developed new ink only lasted 60 years (down from 100) but significantly increased the inks ability to hit those saturated colours. The gamut of the UltraChrome ink is almost as big as the previous Dye inks and can easily simulate an offset or web press when used for proofing.
The Dot Debate
Do we need to see a halftone dot to approve a proof for press? The industry is slowly changing their perception of what a proof should show. Many agree that it is not always necessary to see a halftone dot. Generally a proof is used to approve colour which is easily accomplished without seeing a dot. However there are situations where an incorrect screen angle can result in a moir’ that would not be evident on a continuous tone proof.
Personally, I question the inkjet’s ability to show a sharp enough halftone dot. Once inkjets can print at 2880 dpi as quickly as 720 dpi, then we will see inkjet proofs showing a true halftone dot. Would you accept film or plates that were imaged at 720 or 1440 dpi?
The viewing environment can have a dramatic impact on how colours are perceived. This is even more important for inkjet proofs than it was with traditional analog proofs.
Inkjet proofs are prone to a phenomenon called Metamerism. Metamerism is when the colour temperature of the light used to illuminate the proofs changes the perceived colour. 5000 Kelvin or D50 is the purest light we can view proofs under. All other temperatures will add yellow, red or blue to the proof depending on the colour temperature of the bulbs. When viewing inkjet proofs it is imperative that it is viewed under the same colour temperature as the press is using. Almost all press-viewing areas use 5000 K bulbs.
Soft proofing is simply using a high quality, calibrated and profiled monitor to view your proofs. There are two similar options when it comes to soft proofing, the turnkey or build your own system. Two vendors, Kodak Polychrome Graphics and Integrated Colour Solutions, currently offer SWOP-certified, monitor-based proofing solutions.
Recently I attended a digital proofing shoot-out in Chicago and out of the 26 vendors involved, two were employing monitors for proofing. The monitors ranked 6th and 13th out of 26 well-known industry-proofing systems. That’s very promising for the state of monitor proofing. I predict that in less than five years we will see large plasma monitors at the press being used for proofing.
One of the biggest obstacles to monitor-based proofing is the loss of that tangible piece of paper. Sometimes you need to fold and flip the proof to get a feel for how it will be perceived by the end user.
You can use soft proofing to:
- View it for colour and content.
- Mark it up within Adobe Acrobat, Remote Director or RealTimeProof.
- See how the images will print on the final stock via paper white simulation.
- View spot colours.
- View Ink Limit warnings.
- View two proofs side by side.
- Provide a legal sign-off.
- Let several people view the proof simultaneously or consecutively.
- Archive the proof for later viewing
Acrobat 7: Print Production Tools
Acrobat 7 is packed with great soft-proofing tools such as previewing an image’s Total Ink. Let’s say your printer tells you to make sure all your images fall under 290 in total ink, but you’ve already created PDF’s of your work. Just open the images in Acrobat 7 and select Tools/Print Production and Output Preview.
Before you can soft proof in Acrobat, you need to calibrate your monitor with a colourimeter and turn on Colour Management in Acrobat’s Preferences. The best choice is to use the U.S. Prepress Default.
When purchasing or creating proofs, it is important to keep on top of the devices’ calibration state. This can be done with an Eye-One or a Pulse strip reading spectrophotometer and proof validation software. ColorMetrix, has a beta version called GcX which offers automatic process control charting, a simple pass/fail quality indicator and is not OS dependent. This option will sell for under $900 (Cdn).
Inkjet proofing is still in its adolescence and we still have a way to go before you can walk into any shop, purchase a proof and feel 100% confident in it’s ability to match the press. However, if we go back 5 to 6 years and consider the options we had—IRIS proofs, very expensive film proofs and dye sublimations proofs—then I feel we’ve made great strides. We just need a few more years to weed out that old equipment and start seeing proofs made on current RIPs and printers that are very capable of producing amazing results.
Overview of Colour Management
If you are new to colour management you may find that many of the concepts and practices are overly complicated and full of twists and turns. There are also a number of ways to explain how the process works and how to put those theories into real world usage and real world usage is what it is all about. Sure we can learn how Lab is a perceptual colour space that reflects how the eyes see colour. But does that help us understand how to make our screen match our printer?
The Basics: The goal of colour management is to make colours look the same on a variety of devices—that’s it. It is all about making colour conversions, based on very specific information, supplied in the form of an ICC profile.
How do we translate from one language to another? We use a dictionary to define what the words mean and we use those meanings to translate from one language to another. We use the dictionary to decode the foreign language into words we understand. Every language has a very specific dictionary that accurately describes the meaning of each word.
Colour Management uses similar principles. We translate from one colour space to another hoping to maintain the integrity of the original. In colour management, the ICC profile is the dictionary. This colour dictionary describes how a particular device speaks or paints colour. For example, an RGB monitor has a specific colour language and in order for you to see an accurate rendition on screen, Photoshop needs to speed-read the monitors ICC profile to understand exactly how it interprets colour. Armed with this ICC profile Photoshop can effortlessly and accurately display your image.
The most important part in this process is how accurately the profile describes the device. If a language dictionary were only 80 percent accurate we would never consider using it. But all too often in graphics, monitor or printer profiles are not accurate descriptions of the device and the result is a poor translation from one colour space to another.