Sources of Information about Inkjet Print Permanence Testing
To enable wide-format printers to be used for more than technical drawings, inkjet printer manufacturers made substantial investments in print permanence testing. They wanted to ensure that the inks and materials they developed for photo or graphics printing could withstand typical display requirements.
Print permanence testing was necessary because the first aqueous dye inks and papers used in desktop office inkjet printers and wide-format printers for technical documents faded rapidly when the unframed prints were used for projects other than presentations, everyday proofs, or indoor posters.
When choosing wide-format inkjet papers, you may see some print permanence tests mentioned in the product descriptions on the spec sheets. Print-life projections can help you determine which materials are most appropriate for the type of job you have in mind.
Efforts to create internationally recognized test standards for print-permanence tests were complicated by the huge number of variables that exist in how inkjet prints are created and used.
For example: the longevity of the print is affected by complex interactions of a combination of factors:
- the type of ink used
- the type of inkjet media used
- the environment in which the print is displayed
- how the print is protected from UV light, ozone, humidity, and abrasion
To learn more about print permanence testing, here are three organizations that have conducted print-permanence tests for the aqueous wide-format printers used by many Freedom Paper’s customers.
Wilhelm Imaging Research
Wilhelm Imaging Research, Inc. was founded by Henry Wilhelm and Carol Brower Wilhem in 1995. At that time, the first color wide-format inkjet printers were just beginning to be used for signs, photo enlargements, and art prints. Henry and Carol Wilhelm were already well known for their expertise in the stability and long-term preservation of photographs and motion pictures. So it was natural that photographers, artists, and inkjet printer manufacturers would seek their advice on the potential of using wide-format inkjet printers for photo and art prints.
Wilhelm Imaging Research has subjected prints made with widely used combinations of inks and media to a series of accelerated light exposure and dark aging tests. The tests address the question: “How long will this image last before noticeable fading and/or staining occur, and under what conditions?”
The tests results are published as Display Permanence Ratings so inkjet-printer users can make apples-to-apples comparisons about tested products. Wilhelm Imaging Research has conducted print permanence tests for papers and inks from HP, Epson, and Canon and many manufacturers of digital printers and papers.
The published reports enables you to compare projections for how long a print can last under four different types of conditions:
- framed under glass
- framed behind a filter for UV light
- displayed indoors away from a window
- stored in an album at 73 degrees and 60% relative humidity
The reports also note whether the prints have a high level of resistance to high humidity and water and how many years an unprotected print might be resistant to ozone. If the paper includes UV brightening agents to provide a white surface, it is noted on the report.
The Image Permanence Institute
The Image Permanence Institute (IPI®) at the Rochester Institute of Technology is an independent, nonprofit laboratory that evaluates image stability and photo storage and framing materials. IPI can provide standardized and custom tests for abrasion, light-fastness, air pollution sensitivity, and high-humidity sensitivity.
The IPI primarily uses imaging research to help libraries, archives, and museums understand how to preserve printed documents and images. But they also offer insights that can help individuals preserve their most treasured family photographs.
From the publications page on the IPI website, you can download “A Consumer Guide to Understanding Permanence Testing.” Published with support from the Eastman Kodak Company, the guide explains factors that affect print permanence and discusses four different photo printing methods: silver halide (darkroom processing), inkjet printing, electrophotographic printing, and dye diffusion thermal transfer prints.
The IPI notes that “Three types of changes are generally studied in image permanence testing: fading of the colorants that make of the image, migration or bleed of the colorants, and yellowing of the paper on which the image is printed.”
In prints that experience overall fading, all areas of the image gradually become lighter at an even rate.
Users of inkjet prints sometimes notice that one or more of the colorants in the prints is fading more quickly than the other colorants. This type of fading is called a hue shift. For instance, if a magenta dye ink fades faster than the cyan, yellow, and black ink, the printed photo will have a greenish hue:
The IPI guide to permanence explains some of the limitations of different types of permanence testing and why informal tests (such as placing an image in in a window for a few weeks) can be misleading.
The IPI also conducts tests related to the boxes, portfolios, and poly sleeves used to store digitally printed photographs.
HP Image Permanence Lab
HP operates its own Image Permanence Lab because HP printers, inks, and inkjet materials are used to print everything from exhibition photographs to outdoor signs, billboards, and banners. Materials designed for different types of applications undergo different types of image permanence tests.
For instance, HP materials designed to make prints for home or office display undergo image permanence testing under common indoor lighting and environmental conditions. HP uses both their own Image Permanence Lab and Wilhelm Imaging Research to conduct these tests.
If certain HP materials are likely to be displayed in store or office windows, HP Image Permanence Lab testing uses methodologies that take into account that the graphic will be exposed to partial or direct sunlight.
For materials designed for making outdoor banners and signs, the HP Image Permanence Lab performs tests in accordance with industry-leading standards. Print samples are exposed to real-life conditions at multiple U.S. test sites. Testing measures a range of environmental conditions, including temperature, humidity, light, and spray. More information can be found here.
A Few Things to Consider
Print permanence testing helped drive the development of new ink formulations and printing materials. Inkjet printable materials introduced over the past 10 years have proven to be much more reliable for use in photographic printing than materials for the first generations of wide-format inkjet printers.
If your in-office inkjet printer uses aqueous dye inks to create colors, you can still print photographic images and colorful displays on many different types of materials. But you may encounter problems if the print isn’t framed or laminated and exposed to high levels of humidity or UV light.
Your best bet for printing photographic posters and displays is to choose your print materials carefully or upgrade to a newer-model wide-format printer that uses pigment inks for color printing.
For outdoor photographic displays, you might be wise to send the job out for printing. Today, many companies that offer wide-format inkjet printing as a service use different types of printers to meet many different durability and quality requirements.
Solvent, latex, and UV-cure inks provide greater outdoor durability than aqueous inks. The photographic quality that can be output on these printers has has been steadily improving.
If you have questions about any of the print permanence tests you see mentioned in the descriptions for wide-format inkjet photo papers or sign materials on Freedom Paper’s website, please call us 866-866-310-3335