The technical challenges revolve around the high-speed processing of ink, i.e. the drying of different inks (dye and pigment) of various OEMs and at the same time retaining colourants on the surface. The more ink is applied the more critical this becomes. Only special grades can cope with the high amount of water based inks and dry them. Uncoated grades with their open structure are a good starting point. Coated offset grades with their closed surface are typically not suitable for inkjet printing.
Drying can be well controlled already. Colour brilliance is increasing. Glossy paper grades are still difficult to make. One big challenge is the difference between what printers are used to in terms of paper haptics and optics, and what they can use with the high-speed inkjet technology. They need to rethink the substrate approach. Inkjet printing should be about how to employ the technology for new ways of communication, and not about replacing one technology (laser, offset) with the other (inkjet). There is no value add in this.
We have further developed and optimized the paper manufacturing of the high speed inkjet portfolio. The larger colour gamut in critical colour areas, such as reds, compensates the magenta weakness of current high speed inkjet systems and thereby enables improved accuracy when it comes to logos or reproduction of images. The increased colour gamut also results in a potential ink saving for printers, reducing costs and increasing printers' competitiveness on the market.
We work very closely with the paper companies and have active relationships with 40 paper mills worldwide, 25 of whom are developing new inkjet treated papers. Another way of co-operating is Kodak's Diamond certification system. We test their papers on our devices and give them a rating on a 5-Diamond scale, so customers will know if a paper is good for a certain application. It's important if you're doing just mono books - you don't necessarily need all the highest ratings.
It's about fit for purpose. With a mono text book, most of the papers offer no problem. If you are going to coated papers it depends a bit on the speed you want to print, and the drying capacity of the printing system. The Proper 6000 press can print at high speeds on gloss and silk and has a better drying system, based on infrared, to deal with higher ink coverages. Humidity evacuation is also another major step forward to make inkjet more viable.
There were problems with colour on uncoated, as the ink would sink very deep into the paper, and it would look a bit faded. That was an issue for many of the vendors but there were always ways around it, such as by choosing different paper, or printing slower. We all learned that you've got to dry as quickly as possible, because that keeps the ink pigments at the surface of the paper, and that meant drying much closer to the printing heads than ever before. We have pre-coat now, and that's a simple solution to that.
Currently, we are trying to work with the paper mills to find ways to make papers geographically available everywhere. It looks like a logistics exercise more than anything else but if we achieve that it will be a very nice gift to the market.
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