Labels often demand a wide variety of print effects. To help out, label printers often use hybrid presses and combination presses (combi-presses) that combine two or more printing techniques – offset, digital, flexo, gravure or flexo printing – in a single machine.

Hybrid printing occurs a lot, especially with the growth of digital print. In fact, today, 70 to 80% of all narrow web printing machines are hybrid presses, combining more than one printing technique in a single pass.

It is very common for certain applications:

• Prime labels: coatings (flexo or gravure), special tactile effects (screen printing)
• Security cards (combination of offset and silkscreen)
• Luxury, beauty, health care and cosmetics (folding cartons with coatings, varnishes and special finishes)
• Combination of digital and conventional presses (variable printing applications for labels and folding cartons)

For example, cosmetics packaging requires exceptional printing and finishing quality. Intense colors and extravagant effects are created by combining different printing methods. Combi-presses enable printing to occur in a single pass, rather than sending a job through a number of presses.

Another example is body care product packaging, where quality specifications and brand requirements frequently change. The products are often laminated or upgraded with hot and/or cold foil. Combi-presses support inline laminating of metalized foils which opens up a potential for huge reduction in material cost, waste and time to market.

Most packaging jobs still require at least one spot color, representing the brand. With the availability of combi-presses, a converter can print CMYK in high definition flexo and getting the most out of detail and four-color images, while printing the brand colors, inline, with a screen press units.

While this certainly makes things easier in the pressroom, the challenge is that it makes efforts more complicated in the prepress department. Until recently, a workflow for a print job that required the combination of different printing techniques could not be automated. The print techniques just required too many different settings for the same variables. Think of different RIP settings, different dot gains, compensation curves, different trapping, and other variables.

This means that these workflows always were interrupted by a skilled operator who had to reroute decisions for given sets of separations. Then the operator had to re-launch (and manage) a number of different workflows, automated or manual, to ensure output of the different image channels for the different processes.

An automated prepress solution
There’s now a way to handle this automatically, eliminating pretty much all of the manual settings.

The solution for combi-press support in a packaging prepress workflow is covered by a number of coordinated systems. A new automated workflow is able to handle separations by tagging them for specific printing processes.

Combi-press support begins in the editors, where a specific printing process is a tag that is assigned to each individual print separation. Quite simply, each color in the entire job is identified as to what type of print process (flexo, gravure, offset, screen, digital) it will be printed. For example, an ink manager plug-in for Adobe Illustrator can support the definition of the printing method for each of the separation channels. This data is embedded in the metadata of the resulting PDF file, so that the workflow engine recognizes the printing method for each separation and can route – automatically – individual separations to specific workflow operations based on the set printing method. Built-in throughout the workflow, different prepress tasks (and specifications, like the amount of trapping) are triggered based upon that tag. As the job progresses, those tags are recognized and acted upon in the prepress editors, in the workflow automation tools and, finally, in any RIP – one that is tied to the workflow, or any third-party RIP tied to any of these presses. It’s a simple, yet unique capability that shortens prepress time-allocation for such printing processes by approximately 50%.

Implementing support for hybrid printing environments in the workflow software results in considerable savings in time, resources and error reduction.

Schreiner Group: Making the most of combi-press prepress technology
Founded in 1951, Schreiner Group GmbH & Co. KG is a growth-oriented family-owned business. More than 800 employees develop, design and manufacture high-tech-products in six production locations to ensure reliable worldwide customer deliveries. The company’s annual sales amount to approximately 125 million euros, of which exports account for more than 60 percent of their business.

The nature of Schreiner Group’s work is very complex. They create high tech labels. Most of their presses are hybrids, utilizing different technologies such as digital, flexo, flatbed screen, rotary screen and offset.

The result is that Schreiner Group has to consider many jobs utilizing multiple printing technologies. Because of the sophistication of its work and the use of hybrid presses, they had to treat files as if they were created for different presses. As you might imagine, different presses require different output settings to print correctly. This could include different line rulings, traps, resolutions, ink settings, and many more variables. This required them to generate different job tickets for each file, or to produce two or three different files for one item, to ensure that the job would be processed correctly.

“We have a job that regularly prints in our plant that requires five different conventional press technologies and one digital press on the same job. We also do security work on a regular basis,” notes Markus Petratschek, Schreiner Group’s head of prepress. “It is much easier for our operators if they do not have to be concerned about output settings.”

“We have tested Esko CombiPress and are very enthusiastic about what it can do. With CombiPress, we are able to adjust the settings and automatically generate files for platemaking. Operators just set the job to ‘print’, and that is it. There is much less user interaction,” adds Stefan Kosak, Schreiner Group’s team leader, prepress. “Without this new technology, our prepress-operators would have to create a number of different workflows for our job files. We would have to activate and deactivate the workflows to handle different portions of each job.”

With CombiPress, the workflow knows which separation channels will require screen printing and which will be printed with flexo. It can create special marks for screen-printing and, for example, add distortion just for the flexo press. This has been done manually in the past, but the technology eliminates operator setups and, as such, prevents them from making errors. The automated workflow will always be set up the same, and will complete the job with logical precision.

“For those operators who process files for output, CombiPress will eliminate about 5 or 10 minutes of work for each job. However, for us, the amount of time saved is minimal compared to the elimination of the risk of mistakes on output,” explains Petratschek. “This is very important for us to ensure 100% quality every time – not by effort but by a stable process. If one plate is incorrect, we have to re-plate and start the entire job again. Occasionally, there are also outside costs we incur for special work. These could also be in jeopardy if the job is set up incorrectly. Now we can be comfortable that we will have a good quality assurance system in place.”

“The Schreiner Group creates very high tech labels, and CombiPress is very important for us going forward. It’s going to make a significant contribution for our company and, I will presume, many other printing plants throughout the world,” concludes Petratschek.

As print shops acknowledge the complexity of combi-press jobs, solutions like Esko’s CombiPress will be more commonplace. Workflow automation helps deliver “zero defect” workflows: certainly a welcome result for the industry.

For more information on Esko’s CombiPress, visit www.esko.com