While there are certainly standardised procedures for Color Management in analog printing processes, there are none for digital printing in this respect. The two methods are extremely different, as digital printing is used in various areas – packaging, labels, large format, textiles, ceramics, glass, etc. The application of Color Management in the digital printing realm is essential when we wish to fulfil the following requirements:

• Application of light inks – To reduce the granularity of low-resolution printing systems in bright areas, light inks are often used in digital printing. The amount of light colors and with which hue light colors are applied must be spectrally analysed, and the transition between light and process inks calculated. In certain color management systems, the calculation result is also represented in the form of a DeviceLink profile.
• Application of non-standard colors – In classical printing, CMYK colors and Spot Colors such as Pantone, RAL, or HKS - are practically standard in the industry. Digital printing, on the other hand, uses color spaces such as CMYK colors whose color locations differ greatly from typical colors. Color spaces may be limited to completely different primary colors – e.g., blue, orange, red, green, yellow, brown, etc. The latter point is mainly used in ceramic printing, where, for example, a clean magenta can only be achieved by adding gold, which may render the price of the ink prohibitive.
• No use for Spot Colors – While flexo printing in particular tends to rely heavily on the use of Spot Colors, offset printing uses Spot Colors only for specific applications such as: varnishing, imaging CI inks, and creating effects. In digital printing, Spot Colors are rarely used, but Spot Colors from the Pantone and HKS environments have to be reproduced using the basic colors. In many cases, this is only possible with a very large ∆E value. Other Spot Colors must therefore be used in digital printing, such as white, varnish, and colors for the pre-treatment of a material, which allows printing on materials that were previously unprintable.
• Use of Gamut Expanding inks – Typically, in offset printing, Gamut Expanding inks are rarely used; digital printing systems are augmented with Gamut Expanding inks such as orange, green, and violet in addition to CMYK inks. This addition of colors can reproduce an extraordinary color range, which in turn enables the printer to achieve color values similar to those of Pantone, RAL, or HKS color systems. Additionally, the total area coverage for Spot Colors can be reduced, which typically has a positive effect on drying behavior and applied thickness of printed inks.
• A diverse array of Substrates – While the classic printing processes are generally limited to printing on paper, digital printing achieves what the latter cannot. In order for a Substrate to be printed upon, the ink must adhere to the Substrate. Many Substrates have to be pre-treated in advance or directly at the printer. Due to different surface textures – rough, smooth, wavy, etc., not to mention the use of opaque and transparent Substrates as well as optical brighteners, especially for fabrics – the spectrum is so wide that one cannot speak of a single color space in digital printing, but rather thousands of color spaces. To optimise and fully exploit the color space of a Substrate, every Substrate should be profiled.

• Various Ink Types – Different methods for printing color images are available on the market. Colors can, for example, be applied by toner particles or ink droplets. There are also different types of inks, such as UV and Water-Based Inks, each of which has completely different drying characteristics. Depending on the printing mode, the glossiness of an ink can also be strongly influenced, and in some cases can replace the varnishing process completely. These variables must be taken into account when profiling if you want to get the maximum color from your printing system.
• Direct and Transfer Printing – How color is applied, as well as pre- and post-treatment of Substrates, strongly influences the saturation and overall color quality of a print. For example, temperature differences in the Calenders (rollers) of a press (mostly used for textiles) can be an essential factor. All processes must be scrupulously carried out to ensure consistent color reproduction. When necessary, Color Management can compensate for small deviations in color.
• Altering Printhead Performance – Printheads are expensive and not easy to replace. Printheads are also subject to ageing, which means that printhead performance inevitably degrades over time. With Color Management, fluctuations in printhead performance can be compensated for by re-linearization or reprofiling a color setup. Adjusting printhead performance by raising the printhead tension can also lead to the desired result.
• Adaptation of Printing Systems – If the same printing systems are used, and these systems are, e.g., of different ages, the printing systems are generally required to print as equally as possible. To achieve this, Color Management can be used to adapt the color of the new printing system to the old system.
• Perception differences – In classical offset and flexo printing, the perception of gray is standardised; the desire for a cooler gray, especially within the large format environment, is gradually becoming an industry necessity. The same demand concerning black is also becoming more relevant. These industry demands have to be standardised via the Color Management, because such a process is not consistent when applying a simple color correction on a print item basis, for example.
• Managing Consumption – Besides making the process as simple as possible and reducing the amount of clicks required to accomplish a specific result – e.g., printing using CMY without black or only black without CMY – the only factor that counts in inkjet printing systems is how much ink is used for printing. Since digital inks are very expensive compared to offset inks, the only viable option with digital printing systems is to reduce the application of ink as much as possible. To achieve this, a Color Management system must have a wide range of options available in order to precisely control ink consumption in terms of the use of gamut-expanding colors and black instead of other primary colors to replace dark colors. There are no standards in this area, as each print can be printed in multiple ways depending on factors such as the colors used and the number of colors printed.

As we've read in the previous paragraphs, this subject is very complex. The user has to have a great level of understanding if they want to obtain the greatest possible color application. It is often necessary, at the same time, to save money on printing ink as well as to use Spot Colors or try to achieve a similar result compared to an existing offset print job. All in all, quite demanding.

In this respect, the challenge in developing the used application was to integrate this complex topic in an understandable and, above all, transparent way in one user interface. The possibilities offered by the application in terms of Color Management are enormous – those who engage and master handling colors will save money and be able to deliver print results that can satisfy any customer.