SPECIAL SECTION: Colour quality guarantee

17 February 2010



Digital printing technologies offer a wide range of services for label converters. ExxonMobil Chemical provides the high standards of quality, efficiency and cost that its customers require, along with its 100% colour guarantee


Digital printing has become a mainstream technology for label converters. The use of digital technology can be summed up in a few impressive numbers:

¦ 1,000 narrow web digital presses are in production today

¦ 36% increase in Indigo printed label volume from 2007 to 2008

¦ 170 to 200 new digital label presses are bought each year

The engine driving this rapid growth is value creation. By adopting digital printing technologies, label converters can offer a variety of valuable new services to their customers. Recently, Tarsus Group surveyed the market to discover what label users valued most among the service improvements that digital technology can offer. When the results were compiled, four benefits topped the list:

¦ Speed of response

¦ Reduced inventories

¦ On-demand deliveries

¦ Promotional possibilities

Digital technologies are the ideal platforms for delivering these benefits because they allow the converter to quickly switch from one job to another without excessive waste.

Colour at speed

For label converters, speed is only half of the objective. According to a study by IT Strategies, the primary purpose of consumer product labels is to sell the products that they label, and the standards that these labels must meet are among the highest of any print market.

This is especially true for colour standards. Colour quality is a key element for achieving visual appeal and protecting brand identity. In conventional printing, these requirements are so stringent that label converters match critical colours in the ink room. Done well, the result is an ink recipe that the press can reproduce with little variation during the run. The downside is that the ink matching process requires a substantial up-front effort and still takes a large amount of time (half an hour is considered fast) to obtain an initial colour match on press.

Thus, the key to delivering the full benefits of digital printing is the ability to match colour with the minimum changeover downtime. Because the human eye has the ability to integrate individual dots of pure colour into a single perceived shade, digital presses can achieve this goal without the need to prepare spot colours in the ink room. Instead, colours (including critical colours) are rendered by combining dots of four to 12 primary inks. While this process eliminates the need to mix and match special colours in the ink room, it allows little room for error. A 2% error in either the colour formulation or dot area is readily detected by the human eye, and complying with conventional colour tolerances using this technology pushes colour control to its limits.

Begin with better dots

The starting point for matching colour at speed is dot control. Because any variation in dot size will immediately be detected as a shift in colour, colour quality begins with dot quality. For HP Indigo presses, ExxonMobil Chemical’s patented coating technology provides a new level of dot consistency, and is the basis for matching colour at speed.

Figure 1 demonstrates the impact of the substrate on colour consistency. A process blue has been rendered by overprinting magenta and cyan dots on two different substrates. The substrate on the top is an ExxonMobil Chemical Digilyte oriented polypropylene (OPP) film with a proprietary coating. The substrate on the bottom is a paper with a different digital top coat. While both substrates are HP-certified, the difference in dot quality is visible even to a casual observer. The dots on the ExxonMobil Chemical film are highly consistent in size and shape. The dots printed on paper exhibit a range of sizes with many small and broken dots.

Clearly, there is a difference, but is this due to the smoothness of the filmic substrate or to the chemistry of the coating? Figure 2 has the answer. To separate the effects of surface roughness from coating chemistry, a third substrate (middle column) was introduced. This substrate is a synthetic paper with the same coating chemistry as the Digilyte film, but modified with fillers to achieve a surface roughness characteristic of paper.

When the three substrates are printed with 10% cyan dots (under identical printing conditions), it is easily seen that substrates with similar coatings (Digilyte film and synthetic paper) behave the same, while substrates with similar surface roughness (synthetic paper and semigloss paper) behave differently.

Taking this comparison a step further image analysis software was used to quantify the similarities and differences observed visually. The Digilyte film coating results in 100% dot transfer (35 of 35 dots) on both the smooth and rough films, while the digital top coat on the semigloss paper transfers a variable number of dots (26 of 35 dots in this sample, but more or less in other samples).

Similarly, the standard deviation of dot area for the dots printed on the ExxonMobil Chemical coatings is roughly half of the standard deviation of dot area for the dots printed on the paper coating. Since 10% (or even smaller) dots are frequently required to accurately match Pantone colours, this difference in dot consistency is more than a matter of academic interest. It can make the difference between achieving and not achieving a commercially acceptable colour match.

Colour-guaranteed printing

What label users really want is to make smart choices between cost and quality with the assurance that they’ll get what they’re paying for when the actual labels are delivered. The ability to guarantee dot quality is the starting point to fulfilling this wish, but to fully meet the demands of the users, more is required. Today, ExxonMobil Chemical and EskoArtwork have joined forces to meet this need through colour-guaranteed printing.

Colour-guaranteed printing begins by using EskoArtwork’s industry-leading software to colour separate the label graphics. This software provides the best match that can be achieved within the physical limitations imposed by the starting ink set (for example, four or seven ink colours). While it costs less to print with fewer colours, the visual impact of limiting the number of colours varies enormously from design to design.

Traditionally, the only accurate way to assess the trade-off between cost and colour quality has been to print the design multiple times using different ink sets and conduct a side-by-side comparison of results. However, with colour guaranteed printing, EskoArtwork software with ExxonMobil Chemical PacVantage technology allows label users to replace expensive press proofs with fast, economical inkjet proofs.

Finally, once the user has selected an ink set and a proof, ExxonMobil Chemical guarantees that it can match that proof with little or no adjustment on press, so long as the design was prepared using EskoArtwork software with PacVantage technology and printed on one of ExxonMobil Chemical’s Digilyte OPP films.

Altrif Label experience

Altrif Label BV is one of the largest selfadhesive label printers in the Benelux, producing labels to serve a wide variety of markets and products. It produces high value, custom-made paper or plastic labels for its customers.

Altrif Label has been using this technology for over a year. Eric Graumans, Altrif Label’s production manager, sums up the impact in a single phrase: ‘Thanks to PacVantage software, we have made an enormous step in quality and efficiency.’

Dion Goderie, general Manager of Altrif Label, adds: ‘PacVantage technology contributes to our high customer satisfaction rate. Digital production can be proofed up front with a colour guarantee.’

About ExxonMobil Chemical

ExxonMobil Chemical is one of the world’s leading petrochemical companies with manufacturing, technology and marketing operations around the world. The company delivers a broad portfolio of products and solutions efficiently and responsibly, with a commitment to creating outstanding customer and shareholder value.

ExxonMobil Chemical endorses the principles of sustainable development, including the need to balance economic growth, social development and environmental considerations.


Figure 1 Figure 1. A process blue rendered by overprinting magenta and cyan dots on two different substrates: top, an ExxonMobil Chemical Digilyte™ OPP film with a proprietary coating; above, a paper with a different digital top coat. Figure 1 Figure 2 (a) Figure 2 (b) Figure 2. Three substrates − (a) Digilyte OPP film; (b) a synthetic paper with the same coating chemistry as the Digilyte film; (c) paper with digital top coat − show that substrates with similar coatings behave the same while substrates with a similaFigure 2 (c)

External weblinks
Converting Today is not responsible for the content of external internet sites.

ExxonMobil Chemical
ExxonMobil Chemical
ExxonMobil Chemical

Figure 2 (c) Figure 2 (c)
Figure 2 (b) Figure 2 (b)
Figure 2 (a) Figure 2 (a)
Figure 1 Figure 1
Figure 1 Figure 1


Privacy Policy
We have updated our privacy policy. In the latest update it explains what cookies are and how we use them on our site. To learn more about cookies and their benefits, please view our privacy policy. Please be aware that parts of this site will not function correctly if you disable cookies. By continuing to use this site, you consent to our use of cookies in accordance with our privacy policy unless you have disabled them.