Flexo, hybrid or digital – which is best for short runs?

As run lengths continue to come down, label converters are forced to think hard about which combination of print and converting systems is best suited to their evolving business needs.

Let’s look at the choice between flexo, hybrid (flexo+digital) and standalone digital with off-line finishing.

The boundaries between these technologies are fluid and constantly shifting.

Until relatively recently, we would have discounted flexography as a viable short-term printing method. However, increased levels of automation and integration with digital networks have changed this situation. The industry has found new ways to automate key elements of the flexo process. These include automated pressure setting systems capable of tracking press speeds, plate cylinder presetting, automated cross and print direction registration, substrate-dependent tension presetting, in-line defect and color monitoring, modular control systems, and the ability to store all these parameters for repeat jobs.

Add to this quick-change sleeves, high-speed semi-rotary die-cutting and 7-color ECG inking systems – meaning print units do not have to be washed down between jobs – and you have a powerful machine tool capable of rapid makereadies with minimal waste.

Well over 70 percent of short-run jobs are, in fact, long-run jobs broken down into multiple smaller batches for just-in-time delivery. So, the key metric is how quickly you can get a repeat job back onto the press and print sellable labels with minimum waste.

Automated flexo presses, as described above, are well suited to this kind of short-run environment. The cost of flexo plates is amortized the more times the same job is re-run.

In addition, digital print bars allow flexo presses to print variable data, such as unique 2D codes or serial numbers, screen-replacement white or variable varnish, creating a new category of hybrid press.

Digital and hybrid

Turning to digital, historically, converters have chosen standalone digital presses with off-line finishing.

In the early days of digital printing, the reason was clear: digital print engines were slow and could not keep pace with finishing lines, so it made sense to keep the print engine working and finish off-line (though interestingly, Xeikon in the 1990s was an advocate of in-line finishing through partnerships with Mark Andy and Agfa, and Indigo worked with Gallus to produce the in-line DO-330).

This situation has been turned on its head by the astonishing increase in speed and overall productivity of digital presses over the last few years. Now, we are looking at speeds of 75-120m/min (242-393ft/min), which approaches real-world narrow web flexo speeds.

So now it makes more sense to add in-line coating and finishing to the digital print engine.

The most common flexo integrations are to add print primer and first-down white flexo stations before the digital engine, to add cold foil either before or after the digital engine, and to add varnish stations – including digital varnish – and sometimes flexo spot colors after the digital engine.

Semi-rotary die-cutting technology has reached speeds of over 150m/min (492ft/min), so it can easily keep up with these faster digital print speeds, and of course, there is no requirement to change format sizes between jobs. Automatic die ejection means the only manual operation is loading the die.

Of course, hybrid presses also take advantage of all the flexo automation factors we have noted above in their conventional modules.

We know this as a hybrid press configuration. However, some press manufacturers have chosen their own terms to reflect what they say is a tighter integration of digital and conventional units. Bobst, for example, uses the term ‘All-in-One’.

We are also seeing the incorporation of 7-color digital print engines into converting lines, effectively producing a hybrid press. This can be seen, for example, in the recent joint venture hybrid developed by Grafotronic and Domino for LP2i Étiquettes in France.

What’s next

Will flexo automation and greater hybrid productivity start to squeeze out standalone digital presses with off-line finishing?

No, and for two reasons.

Firstly, many converters’ job mix will always favor maintaining maximum productivity on the digital press and finishing off-line without any interruption to set up conventional print and converting units, however automated.

Secondly, we are at the beginning of an exciting process of automating off-line finishing machines. Mercian Labels’ 2-year JDF/JMF automation program, carried out with ABG, Screen and Cerm, points the way to this future, where responsibility for machine setup shifts from machine operators to remote job programmers.

The digital press prints at full productivity, and each SKU carries with it, in the form of a barcode, instructions on how it should be finished.

Each of these technology strands will take a leap forward at Labelexpo Europe 2025, providing the label converter with an unprecedented choice of strategies for handling short-run work.