Chemical labels, either for industrial or household use, must appeal to the consumer, be UV light resistant, resist chemicals and mechanical stress. For these circumstances, Xeikon generally recommends its UV inkjet technology, although dry toner can also come into play when a higher image quality is desired.
1) Look and feel
Dry toner gives a matte impression which, by applying a varnish, can give a glossy look. When fine image details (offset quality) are required this technology is preferable. UV inkjet gives a very high gloss and tactile impression, which can appeal to certain people. The image details are not as sharp as dry toner but this is not necessarily a requirement. In this case, the choice lies with the brandowner.
2) UV light
Lightfastness is critical for high quality labels. It is a measure of how well a printed image resists discoloration or fading as a result of exposure to light over time. Products sitting on a store shelf or in a warehouse are often exposed to direct sunlight for hours on end. The UV affects the color pigments, causing the image to lose its brightness over time. It is a natural process which can be slowed down by adding protective UV layers on top of the label (varnish or laminate). From the start, Xeikon invested in high quality pigments used in the dry toner and UV inkjet inks with great lightfastness scores without any additional protective finishing.
3) Chemical resistance
Cross-linked systems are generally highly resistant to chemicals, which explains the performance of UV-curable inkjet inks compared to that of toner: the resins in dry or liquid toner are mostly not cross-linked. Applying chemically-resistant lamination remedies this issue. The chemical resistance of water-based inks is due to the fact that these inks do not contain any components with an affinity for chemical solvents.