Flexo has historically been regarded as a comparatively simple print process, not capable of producing the same quality as offset or gravure. However, thanks to technological advances in colour matching, automation, and platemaking over the last decade, the quality and capabilities of flexo has dramatically improved, writes PIOTR WNUK of Labels and Labelling magazine.
The investment by Polyflex in Crystal technology now offers consistency and repeatability whilst maintaining sharper text, better highlights, and little dot gain. This is an ideal foundation for successful ECG printing.
Expanded Colour Gamut (ECG) printing, often referred to as a fixed colour palette or simply extended gamut, uses a standardized ink set to reproduce a wider range of colours used in design by adding – usually, but not always, orange, green and violet – to a conventional 4-color process set-up. Moreover, this method enables nesting of print jobs with different colour channels, without changing the ink configuration of the press, therefore increasing performance, and minimizing downtime.
While 4-color offset printing can usually achieve around 65 percent of the Pantone book, 7-color printing can further expand this percentage range to 90. Pantone estimates that between 15 and 25 percent of all packaging internationally is printed using ECG (based on printers using ECG software) and expects this ratio to increase by more than half over the next decade.
Using ECG can help to reproduce a design with more eye-catching colours, achieving a print result closer to the original RGB design. This is especially important in the consumer-packaged goods sector, where manufacturers often increase product options with variations of flavours, pack sizes, and regional information required on the packaging. This is where ECG can offer an attractive way to improve the visual impact of a package on a shelf.
Consistency and repeatability
Today’s packaging must promote as much as protect, and that has an impact on the supply chain. Customization and personalization mean shorter runs and more frequent design changes, so that creates more pre-press. The designs are more complex, so they require higher print quality. Consumer demand for sustainable packaging means printing on new, sometimes lighter substrates. There is a dynamic demand for all the above, without drop in quality or cost increase — which also goes for the brand owners, who also want faster turnaround. So, there is something of a tightrope between all these factors.
It is common today for converters to run 150 LPI, and many have made the jump to 175 or 200 LPI along with the ability to fade screen vignettes to zero. These specifications would have been virtually impossible just a few years ago. The ability to print fine screen rulings and fade screen vignettes to zero has made a resurrected technology possible, by printing with ECG.
Win-win situation… for some
The demand for shorter runs of flexible packaging, for targeted marketing campaigns and product variations, are increasing especially within the consumer-packaged goods sector, therefore converters need to meet these challenges in a timely and cost-effective manner.
The elimination of spot colours and converting them into a fixed ink set can reduce downtime between the jobs and ink inventory, increase productivity with fewer wash-ups and the option to nest jobs on the press. It can also reduce waste and enable faster press running speeds due to a thinner ink film.
The key consideration is, however, achieving a smaller range of colours. For some brands, the spot colour will be imperative from a marketing point of view; for others, CMYK ECG might be considered an opportunity for significant cost savings and a chance to redirect the printing budget to other activities.