Written for Image Magazine
UV Curable printers have some distinct requirements when it comes to colour calibration because of the unique nature of some of the substrates that customers want to print directly to. Glass, rear illuminated acrylic, steel, aluminium, pre-treated boards and metal, and yet the customer expects colour accuracy on these materials.
When some of these materials are expensive or only available in limited quantities then the ability to quickly achieve the accurate desirable colour with the smallest wastage of time and materials is critical. Most people are aware that your solvent printer needs a profile for your vinyl; a UV curable printer has exactly the same colour requirements.
For best results each substrate should have a custom calibration and profile (built on machine), with the single exception that some UV printers have white ink that can be used as a pre-treatment between the substrate and the actual coloured ink. In this instance the White ink is printed and cured in advance of the colours, giving the coloured ink a consistent surface regardless of actual substrate, meaning that in this example only one profile should be required for front illuminated prints across many products.
For UV printers that don’t have white ink as in this example, or where rear illumination is required you need to generate a new calibration and colour profile per substrate. This originates from within the rip that drives the printer, in conjunction with spectral measurement equipment such as a spectrophotometer. In our testing any surface that is textured requires more specialised equipment than the simple i1 style device due to the small, fixed aperture size of the measurement area.
The only product that we have found suitable for textured surfaces (such as canvas, fabric, some banner, and other similar specialty products) is the Barbieri Electronic “LFP”. This LFP has a number of extremely unique features aimed squarely at UV curable flatbed and hybrid printers, such as the option to select between both a 2mm, and 6mm measurement aperture (perfect for accurately measuring textured surfaces). It can measure in both reflective (for front illuminated prints) and transmissive (for rear illuminated prints) completely automatically including positioning, up to a staggering 20mm depth substrate. This is the only device in the world that has these mandatory requirements for the UV flatbed owners looking to manage colour accuracy. This device allows automated, and very fast measurements on a range of products that are otherwise unable to be calibrated or profiled.
If you would like to discuss colour on UV flatbed printers further Cielab have launched a unique forums site focused on: colour management, rip, and printer related topics that is open to anyone free of charge at “cielab.com.au”. If you would like to know more about the Barbieri Electronic range of products contact cielab on 1300 243 522 find out more about the mentioned LFP device.