We’re starting to see a lot of digital options being introduced in the packaging sector, particularly on the labelling side. Indeed, we’ve already reported on the rise of hybrid inkjet and narrow web flexo presses that were shown at the last couple of Labelexpo shows and we’re fully expecting to see a number of much wider inkjet and hybrid presses at this summer’s drupa show. In addition, extended color gamuts could offer savings in both time and materials to flexo printers.
In most cases, digital printing in the packaging sector is introducing a short-run alternative to flexo printing. But flexo printing is characterized by the heavy use of spot colors, both to pick out company logos and to make images more vibrant. There is an alternative – to use a fixed color gamut, sometimes known as extended gamut color printing. It’s not a new idea, dating back to Pantone’s Hexa- chrome offering from the mid-90s. But its adoption has been held back, mainly because converters want to offer the best image possible and that usually means using process colors with a liberal dose of spot colors.
However, the increasing use of digital printing should lead people to rethink this,
particular hybrid solutions that include both digital and flexo imaging units. Its rare to see spot colors used on digital with vendors working hard to develop wider gamuts for their inks in order to be able to reproduce the widest range of colors from a fixed inkset.
There isn’t a fixed prescription as to which colors should be used. Some people ar-
gue that CMYK should be enough but most flexo printers use a seven color ink set,
usually CMYK plus orange, green and violet though there are some variations. Also,
some converters may find that a smaller inkset – such as CMYK plus orange – is
enough for the majority of the work they are doing.
There are two main benefits to adopting extended color printing in flexo production. The first is the savings that come from reducing the makereadies between jobs since there’s no need to change spot colors. Most converts report that they are facing increasing demand for shorter run lengths, which means of course that they have to cope with much faster changeovers between jobs. So moving to an extended color gamut is one way for them to cope with this.
The second benefit is harder to quantify but many converters report better print results with more consistent colors. Some argue that this is because it’s easier to establish good process control but others feel that only companies that have properly mastered their process control can really get the full benefit out of using extended gamuts. But it’s certainly easier to establish a standardized way of working with a fixed inkset.
However, although most experts agree that using a seven color inkset does lead to better results than four colors, those results are still not in the same league as dedicated spot colors. Steve Donegan, managing director of Graphic Republik says, “You have to be upfront with the brand owner over how the print will look and the cost savings. Some brand owners are very precious about their colors until you tell them how much they could save.”
There are a number of applications available. Kodak, for example, sells a programme called Spotless that can convert spot colors to process colors. It can cope with between four and seven colors by simulating the spot colors as tints of the process colors.
Grant Blewett, Kodak’s global sales director for packaging, says that Kodak’s Flexcel NX system can achieve a much wider color gamut than other flexo systems, adding, “We understand that there is a significant amount of the Pantone Guide that can’t be addressed with four colors.
But we have enlarged this space so that we can now ask how much work can be done in a 4-color build.” The press has to be finger-printed and the software then maps the colors to the theoretical color gamut that a press can achieve.
Esko’s main offering is the Equinox system, which is a collection of different products and services ranging from software to profile equipment and converts jobs to assistance from Esko’s consultants. It relies on making a profile of the press, complete with the customer’s chosen inkset. At its heart is a tool for optimizing the print build. David Harris, product manager for Esko’s color products, explains, “It can be that the accurate build has a small percentage of black or another ink and we can make a better build by zeroing that ink out which reduces the amount of ink in the build and makes the result more stable and leads to higher quality.”
Esko has a Photoshop plug-in for processing extended color gamuts in images. However, this relies on someone manually editing the file to their own preferences. Harris explains, “You can save the ink transformation as a device link profile which means that you can use that transformation on images in an automated workflow. So if you had a lot of very similar images then you can apply that same transformation to all of them.”
Graphic Republik sells an alternative called MaxColor. This allows you to substitute some of the CMYK colors with the spot colors used in a given job. Donegan says that this saves on the number of plates used for a job, adding, “If you can print with less colors then you get better trapping.” He adds that it works directly from the Pantone spot library whereas Photoshop uses RGB and CMYK values for reference.
Another option comes from Opaltone, which mixes primary colors red, green and blue with the CMYK process colors. The main part of the system is the Opaltone CX software, which is a Photoshop plug-in. It automatically separates both the artwork and the images – though the images are converted to CMY+RGB.
However, converters must use inks that have been certified by Opaltone and calibrated via an OT7 target, which provides density targets throughout the tonal scale. The converters themselves also have to pass an OT7 certification before being given access to the system.
There’s also a VK system suitable for inkjet, which uses CMY+RGB inks, so that proofers can be OT7 calibrated. This comes with its own VK Proofing RIP.
Finally, its worth coming back to where we started with digital printing. Most vendors developing digital or hybrid options for the packaging market see CMYK as being the standard colors, though none of these have an inkset that can hit the full Pantone library. This is particularly noticeable for the packaging market because of the heavy use of Pantones, both for brand logos and to accentuate individual colors.
The result is that some of the more recent digital offerings do now have a larger number of colors. Thus the Gallus DCS340 has eight inkjet colors – CMYK plus orange, violet and green as well as white, which is sometimes overlooked but absolutely essential in labels and packaging. Most people could probably also benefit from a ninth channel for a clear ink or varnish. The great irony is that as the digital vendors are increasing the number of colors in order to keep up with the wide color gamut achievable in flexo, so the flexo converters are experimenting with reducing their inksets to keep up with the short job changeovers of digital!