Brands spend millions on their logos, colour schemes and packaging designs. Maintaining a consistent brand is strategic and critical for all of them. If a brand’s colours are inconsistent across different packaging or customer touch points, it may suggest a lack of quality and can cause confusion and less brand loyalty.

Up until very recently, colour consistency has remained very challenging to implement.  The sheer variety of printing processes, inks, and substrates have created a significant challenge for brand owners and converters to achieve colour consistency. Some substrates, such as paperboard and corrugated cardboard are more absorbent, which can affect how the colour of the substrate itself interacts with the ink and affects the colour. Substrate isn’t the only consideration either – there’s various printing processes, from offset, flexo and gravure to digital printing, and all use different types of inks.

So, we can say with confidence that colour consistency is a big challenge for printers and converters.

“This is becoming a real priority for brand owners now,” said Federico D'Annunzio, Head of Product Development for DigiColor Technology at BOBST. “Until recently, there was only a little culture of colour management within companies, but now it is growing and becoming strategic. And it is not enough anymore to have colours that appear to match with the naked eye. The industry has developed very advanced instruments that can measure the precise Pantone colour. There is nowhere to hide for converters on this issue, and it is our job as a supplier of equipment and services to find solutions through innovations.”

Solving colour consistency – ECG and beyond

BOBST recognised the urgency of the challenge years ago and put several initiatives in place to find solutions.

For example, it founded the REVO project, a hugely ambitious flexo industry initiative involving multiple partners, which aims to ‘digitally’ standardise and automate the flexo process from pre-press to print delivery. Colour consistency is a major element of this.

The REVO 7-color Extented Color Gamut (ECG) printing, developed by the REVO Technology Team of leading industry suppliers, is now a well-established turn-key DigiFlexo process that flows from pre-press through to production output. As well as REVO, there are also other BOBST industry partnerships also aiming to achieve optimal ECG printing, including smartECG, which is focused on flexible packaging.

ECG printing uses three additional ink colours - orange, green and violet (OGV) – on top of the conventional colours of cyan, magenta, yellow, and black (CMYK), enabling a match with 90%+ of the Pantone book, compared with approximately 60% previously. This means there is no need to keep huge inventories of spot colours – the majority of colour positions can be generated without having to use spot colours. But spot colours can still be added if required.

The digitisation of colour matching has made colour conformity with the job master request possible. With the new DigiColor system (see below), brand owners can validate the colours through a digital version of the final product. It means that brand owners can have reassurance around the colour matching of their packaging worldwide, irrespective of the geographical location of the printing facilities or the different ability of the press operators.

“Successful from day one”

“If a converter uses a REVO package, they can start with ECG and be successful from day one,” explained Mr D'Annunzio. “Because REVO packages contain in-line colour measurement and standardisation of all print elements including plate, anilox, inks, pre-press, substrates and inspection, this provides the consistency.  We also provide information and support to converters so that adoption of ECG can be as smooth and fast as possible.”

The latest example of an ECG-ready CI flexo printing solution from BOBST is the 20SEVEN, which has notable improvements in mechanical design and process control to make the machine a perfect fit for the requirements of the  seven colour ECG printing process.

Meanwhile, BOBST also founded Mouvent as its digital printing competence center in 2017. Mouvent has already revealed several printers that can all print up to seven colours on a large variety on substrates – paper, self-adhesive and wet-glue labelstock and flexible materials – at high production speeds and with complete colour consistency.

Corrugated consistency?

What about corrugated? The quality and colour consistency with flexo on corrugated has often suffered, and more complicated images, colouring and photo-quality images are usually not possible. What’s more, the cost of ink and plates can be high, and if any of the artwork is changed, new plates need to be made.

BOBST introduced THQ (Très Haute Qualité) FlexoCloud Technology to change all that. BOBST, along with its industry partner Graphilabel, pioneered a solution that is associated with a large colour range with a four colour process, perfect colour density with solid printing and outstanding quality on a large range of liners. It is associated with ultra-high precision, positive and negative line printing and smooth transitions, from 0 to 100% coverage.

Introducing DigiColor – the world’s first closed-loop system

In 2019, BOBST introduces DigiColor, the very first closed-loop colour control system in the flexo industry. Colour is measured in line and adjusted on each print unit to match – in a few meters – the target colour values. Each of the seven ECG inks is split into a darker and a lighter ink, which are mixed in-line to match the targeted Delta E. DigiColor can make subtle adjustments as needed while printing. For example, if the substrate absorbs a greater quantity of ink than expected, and the Delta E Target is not matched, the system will automatically adjust to utilise more dark ink, ensuring perfect tone accuracy and Delta E colour matching.  The flexibility in colour management that was traditionally exclusive to digital printing and, partly, in offset, is now available to flexo printers.

DigiColor completes the BOBST path to full digitisation of the flexo process. Print pressure, register and now colour, are managed by digital automation (sensors, servo motors, Artificial Intelligence) making digital and digital flexo widely compatible and closer in performances, also on short runs.

For the first time it is possible to transform the final printed product from DigiFlexo back to a digital file to be able to compare it with the original digital native file. The printer extracts digital values from printed job, producing a “digital twin” of the original file. This means that for the first time, brand owners can review a digital twin and validate the colours from the original digital file – no more guessing – just facts. This effectively “closes the loop” starting with a digital file, utilising digital automation to complete the job, and validating the output with another digital file.

“The feedback we have heard from converters – and the brand owners who are their customers – who have utilised our innovations so far, including REVO presses, is that they are extremely happy with the consistency,” said Mr D'Annunzio. “Now with DigiColor we go to the next step – outstanding colour consistency but with an entirely automated process. This is a major evolution and I believe it will revolutionise colour consistency management in the print and packaging industries.”