Comparison of HP, UV Inkjet and Xeikon digitally printed label images exposed to sunlight

The test compared HP, Xeikon and UV inkjet prints over months of sunlight exposure

The test compared HP, Xeikon and UV inkjet prints over months of sunlight exposure

At last weeks Label Expo 2011 a poster caught my eye, comparing the pigment fading of the 3 principal digital label printing technologies in an easy to see and understand way, the best comparison I have seen to date.  Put simply it showed the same image printed at the same time using 3 different processes (HP Indigo solvent based liquid toner, UV cured inkjet inks used by Xaar, Konica Minolta & Kyocera,  and the FDA approved food safe dry toner used by Xeikon), all with an unexposed version , and a version that had been exposed to 800 hours of sunlight from May to August 2011.

The results are dramatic, and clearly show the difference in UV lightfastness between the different technologies.  The HP solvent based liquid toner fades by far the most, followed by the UV Inkjet, with the Xeikon dry toner by far the most lightfast and light stable for high performance labelling applications.

Here are the images – compare the before and after for each process.

Before

After 800 hours

HP Liquid Toner

UV inkjet

Xeikon dry toner

Can you see any difference in the ‘before’ and ‘after’ Xeikon images?

To measure the changes scientifically, a parameter called Delta E is used by colour professionals, and is shown in the table below for each of the colours. A Delta E of 1 is about the smallest colour change that can be seen by the human eye.  A larger Delta E number means that the colour difference is bigger between the 2 versions. Here are the measurements on each of the 7 colours.

Delta E values for the 3 printing processes after 800 hours of daylight

Delta E values for the 3 printing processes after 800 hours of daylight

So its clear that both visually and by measurement of Delta E, the Xeikon dry toner process we exclusively use at Mercian Labels  is the most lightfast digital label printing technology you can use, on average this test indicates that the colour change with a Xeikon dry toner is about 5 times less than when using HP solvent based liquid toner.

So if you are looking for high performance digital labelling for use when exposed to sunlight, make sure you specify a  Xeikon printed image from Mercian Labels to minimise the risk of significant fading.

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