I routinely receive inquires about how long a label will last outdoors–with the hope the answer will be 2 or 3 years. However, the answer depends on who you ask:
- Engineering: it meets Blue Wool Scale 6 and BS5609 based on Xe lamp testing for x amount of hours.
- Sales: it lasts a very long time, which is longer than the competition.
- Marketing: it depends on time of year, latitude and yes requires a special consultant to write a report.
As you can see, none of these responses answer specific questions that converters want to know, such as “Can I stick a label onto a piece of construction equipment for 10+ years?”
Here’s a very helpful white paper by Zeller+Gmelin called Lightfastness of Printing Inks. In addition, checkout the Pira Consultancy Report: Tests on Ink Jet Prints that has data for the Epson L-4033.
And although these documents are excellent starting points, I’ve yet to find an answer that I’m satisfied with. Have you? Till then I will put some print samples on our building’s roof here at 33.8018° N latitude and let you know how they fare later this year.