Images_Digital_Edition_April_2020

www.images-magazine.com 28 images APRIL 2020 TIPS & TECHNIQUES Oliver Luedtke, chief marketing officer at Colorgate, delves into the science of colour management for DTG printing case you print on different models of machine and/or from different vendors. This includes matching analogue/ screen and digital presses to each other. Or matching different products – so a sublimated coffee mug bears the same corporate colours as a promotional T-shirt. Or different facilities: colour management allows you to produce identical colours even when you print some garments in Europe and some in Asia. There is no need to exchange physical samples as colour can be measured and the values can be compared digitally. One word of warning, though: when you colour-match two printing systems, the one with the smaller colour range defines what can be printed on both of them, so you need to be sure what you are planning to achieve. Colour management also lets you get a proper handle on spot colours. Do you sometimes receive print files with embedded Pantone colours (eg classic blue, Pantone’s colour of the year in 2020)? A colour management solution will let you output these colours quickly and precisely, without printing colour wedges and painstaking experimenting. So, how does a colour management system actually work? In order to understand this, you need to differentiate between device-dependent and device-independent colour. ■ Device-dependent colour Colour spaces such as CMYK and RGB are usually device-dependent colour. They are a physical colour definition that will produce different outputs on different systems. For example, when you display a full-tone red on different monitors, you will get slightly different colours as the monitors run on different settings and use different phosphors, resolutions, light sources and much more. That’s why such a colour definition is not suitable for managing colour precisely. ■ Device-independent colour The CIELAB-System is an ‘abstract’ colour space which defines colour in an absolute way. In this system every colour has an L, a* and b* value. Every colour in this colour space is represented by these three numeric values, and they are always the same for one colour. L a* b* values can be measured with spectrophotometers. Creating a colour profile means that you feed a selection of different CMYK T he good news first: the demand for colour accuracy in direct-to- garment (DTG) printing is not as high as in, let’s say, large format printing or the furniture décor industry. The special characteristics of garments and the process that is required for pretreating and curing them imposes a natural limit on the achievable colour accuracy and consistency of your prints, which means that there is no solid reason to colour-manage prints to the extreme. To put this into perspective for those of you that are familiar with Delta E (colour standard) values: when 2-3 Delta E is an acceptable tolerance in commercial printing, then Delta E 5-6 will definitely be acceptable in direct-to- garment printing. Make your life easier But does that mean that professional colour management is wasted on DTG printing? Of course not! Colour management makes your life easier in many ways. First of all, it helps you match your prints to each other. That way, you will receive identical colours on different garment qualities, or between different printing systems, in Oliver Luedtke Industry experts provide insight and guidance in all areas of digital garment and textile printing Digital helpdesk Colour management allows printers to achieve identical colours on different garment qualities and different printing systems