ABOVE: Relative fading after 9 months of window exposure. In rank order; least faded at top left. WINDOW TEST A (being a personal test of a real-world image's print permanence) Third & Final Report: November 20, 2006 (latest reports at top; follow-up comments under each report) I completed this window test on November 9, 2006, removing the test samples after three more months of exposure. The total exposure time was nine months, long enough to see even more changes, although the fading trends had already been established after six months (see Second Report below). This last leg took me from early August to early November of 2006, starting in the hottest and most humid part of the year and tapering off to cool, fall weather in central Virginia, USA. Since my samples were placed on the inside of a home-office window (facing South SouthWest), the climate controls in the house kept the temperature and humidity within a small, normal-comfort-level range (except for localized heating of the print faces due to sunlight striking them). To recap, I had eight small print samples produced with a combination of dye-based inkjet, online photo, and offset lithography. The image was a personal one, not a standardized one, and the purpose of the test was to compare and rank the relative fading (lightfastness) of these samples all exposed to the same accelerated environmental conditions (light coming through my window, 5-6 hours of direct sunlight per day). There was undoubtedly some airflow (atmospheric contamination) over the prints, too, as I had the prints place on the window (face out) with a 1/4" gap between print surface and glass (see photo below of set up). Observations after Nine Months My overall visual ranking (see image at top of page) stayed basically the same as after six months, except that I reversed the the order of the last two, both of which were VERY faded. Here are is the final ranking, least faded at top, similar ones grouped together: 1. HP 8750 on HP Premium Plus Photo paper, 11.5 mil (swellable) -- some visible fading 2a. HP 8750 on Epson ColorLife Semi-Gloss, 10 mil (swellable) 2b. HP 8750 on Ilford Galerie CLASSIC Pearl, 250gsm (swellable) -- obvious fading; roughly the same on both 3a. HP 8750 on Ilford Galerie SMOOTH Pearl, 280gsm (microporous) 3b. HP 8750 on Kodak Professional Inkjet Photo Paper, Lustre, 255gsm (microporous) 3c. Snapfish online print, I'm guessing Fuji Frontier, on "Kodak paper" (wet chemistry) -- these three were in the same range of visual fading, which was more than the ones above, and each one exhibited slightly different characteristics. The Ilford Smooth Pearl looked slightly less faded than the Kodak Professional, but the Snapfish print started to show some "differential fading" or "blotching" in addition to some surface "crackling." 4a. Offset lithography, same image printed in my "MDP2" book (page 376) NOTE: only up for 8 months (added late) 4b. HP 8750 on HP Glossy Brochure and Flyer Paper, bought at Staples as a cheap alternative, 160gsm (coating, if any, unknown) -- both of these exhibited severe fading; hard to tell which was worse, although the Brochure print also showed some differential fading, which probably puts it in last place. ABOVE: The same eight samples but with their left covers pulled off (and in the same ranking order from top left. (The blemishes and spots on a couple of the bottom-row samples are due to the lighting and to the covers sticking to and pulling off pieces of the image.) -- An interesting thing to do is to see how the relative rankings changed from 3 to 9 months. While most samples held their positions (or close to it) throughout the test, the one exception is the Snapfish print. It started off tied for second with "only a hint of fading," but at the end (six months later), it had dropped to sixth place with signicant fading and "blotching" (you can see it on the image at top of page). -- Since I didn't measure the total, accumulated exposure in either lux or joules per square meter, and I also didn't have a simultaneous test running under real-world conditions, I have no way to know how many years of "normal" exposure my window test would equal. Consequently, I can't say which samples would be "acceptable" and which not. But the point of this test was only to do a comparative ranking ("A faded less than B"), and the winner print from the group is very clear: the HP Premium Plus Photo paper. Even though this print also had some visible fading, ALL the others had a significant amount more. -- The final rankings again show me that it's important to match the inks used with the paper coating type. In this case, dye-based inks were used (for inkjet), and the swellable-coated papers that are designed for dyes were the overall top-three ranked. -- Inkjet took the top five of the eight spots, which only reinforces my overall view that inkjet is superior to wet chemistry and offset printing (when coordinated correctly with the right media) in terms of print permanence. And this is only using dye-based inks! ABOVE: (top) my best-testing inkjet sample: on HP Premium Plus Photo paper; (bottom) my worst inkjet test sample: on HP Glossy Brochure and Flyer Paper. The fading differences are very clear. Covered sides on left. White spots at center of bottom print are due to using double-stick tape that pulled off parts of the image; won't do that again! -- Because this wasn't a controlled-length test (I didn't end the test at a known or standard time; I let it run until a point I determined was long enough), there is no way to know if the relative positions would change again if the test were to run longer. However, the basically stable positions of the samples (with the exception of the Snapfish one) to the point of significant and severe fading indicates to me that the sample ranking wouldn't change that much. -- For my purposes, the big conclusion for me (based on this small sample) is that the OEM-recommended paper for this printer was the best in terms of fading. This gives me a small clue that the printer manufactures really do know what they're doing when they say they develop a system of printer, inks, and paper to work together. Of course, it's hard to generalize with only one eight-sample test, but it's one data point for me. If 500 other people did the exact same test in their environments and came up with the same overall conclusion, then that would be interesting! -- And speaking of other tests, now that this one is over, what's next? Well, I've learned some lessons, both by myself and by the comments and suggestions others have made to me. I will definitely do an inkjet pigment-based test next. I will probably include some standardized imagery or image components. I will not do the half-covered/half-uncovered testing samples; too complicated. Instead, I will keep a second set of samples sealed and stored in the dark nearby. And I will also strongly consider using a better control scenario, probably using the Blue Wool standards and maybe the ASTM D5398 standard. ^ back to top ABOVE: Relative fading after only six months of window exposure. Second Report: July 24, 2006 (latest reports at top; follow-up comments under each report) I removed my test print samples after three more months (see 3-month report below). This now makes it 6 months of exposure on my South-SouthWest-facing office window. This last three-month time frame was April 23 to July 23, 2006. Although the sun was higher in the sky, my roof overhangs dropped the full-sun time from just under six to about five hours of direct sunlight. But as Mark Gottsegen notes below, full sun isn't a requirement for this kind of test, although it will probably speed things up. Because I'm now in the hot summer months (central Virginia, USA location), my air conditioning is working, and the average ambient temperature around the prints was about 78 degrees (F) toward the end (I have a little thermometer there to check). Observations after Six Months Look at the image at the top of this page. This is a group shot of each sample as soon as I took them all down, roughly arranged left-to-right by increasing visible fading (least-faded top left). As you can see, and I can report, there is a significant difference in the amount of fading of the exposed portions of the eight samples. Here is my naked-eye visual ranking, least faded at top, grouped together if visually similar: -- HP 8750 on HP Premium Plus Photo paper, 11.5 mil (swellable) -- HP 8750 on Epson ColorLife Semi-Gloss, 10 mil (swellable) -- HP 8750 on Ilford Galerie CLASSIC Pearl, 250gsm (swellable) -- HP 8750 on Kodak Professional Inkjet Photo Paper, Lustre, 255gsm (microporous) -- HP 8750 on Ilford Galerie SMOOTH Pearl, 280gsm (microporous) -- Snapfish online print, I'm guessing Fuji Frontier, on "Kodak paper" (wet chemistry) -- HP 8750 on HP Glossy Brochure and Flyer Paper, 160gsm (coating, if any, unknown) -- Offset lithography, same image printed in my "MDP2" book (page 376) The summary is this: With this dye-based inkjet printer (HP Photosmart 8750), the HP Premium Plus Photo paper (the only one in this group specified for this printer) is the clear less-fading winner after six months; the other two swellable-coated papers (Epson ColorLife Semi-Gloss and Ilford Galerie CLASSIC Pearl) looked about the same and slightly worse; the two known microporous-coated papers (Kodak Professional Inkjet Photo Paper and Ilford Galerie SMOOTH Pearl) plus the Snapfish online print looked similar and worse still; the cheap brochure paper and the book print were VERY faded and basically unacceptable. (Note that the last one is actually offset lithography, and it was put up a month late so it only had five months of exposure time.) But there's more... Review the image below and then keep reading under the caption. ABOVE: All eight test samples with their left-side covers pulled off. Continuing with my observations from three-months earlier: -- As you can probably see in the image above (and I can confidently report), ALL samples showed some fading when comparing their left (unexposed) and right (exposed) sides. Even the top-ranked OEM paper (top left) showed some fading; slight but still visible. I wonder what a pigment print would have done in comparison? Next time. -- The three swellable-coated papers took the top three spots; the microporous papers were more faded. (therefore, I will only use swellable papers with dye-based ink systems unless I post-coat the print somehow or frame it under glass) -- Claiming, as Kodak does, that microporous-coated paper is universal for dye and pigment printers appears not to be true (for me), if fading is the criterion. [Note: Kodak does go into much more detail qualifying dye performance in this 2005 white paper: http://www.kodak.com/global/plugins/acrobat/en/ professional/products/papers/ inkjet/imageStabilityBehaviors.pdf. (copy/paste the above URL is it is broken) Just wish they included that in each paper package! --HJ] -- The wet chemistry print (from Snapfish) is starting to lose ground after six months. (See "Added Comments" below.) -- Another interesting side observation: the markings on the bottom of each print were also faded. These were made with a fine-tipped "Sharpie" (indelible marker). Tip: never use a Sharpie to sign a print! -- Artists who still produce limited-edition prints by way of offset printing are making a big mistake, in my view. After only five months, the offset test print is hopelessly faded. -- Just for fun, I scanned the best- and worst-performing inkjet print samples. I'm sure you can see which is which below. This is the reason why you want to carefully match your paper to the printer's inks. The dye-ink/swellable-paper combination at bottom is designed to provide better print longevity, and the proof is right there to see. ABOVE: (top) my worst-testing inkjet sample: on HP Glossy Brochure and Flyer Paper; (bottom) my best inkjet test sample: on HP Premium Plus Photo paper. The fading differences are obvious. Covered sides on left. So, six months of window testing show clear differences among various dye-based inkjet samples on different media (paper). What's next? Put these up for another 3-6 months? Start a new test with different inks and media? You'll just have to wait and see. -- Harald Johnson Added Comments: July 28, 2006 Photographer Michael Keller posted these comments after reading the report above on the HPDesignJet_Printers forum at: http://groups.yahoo.com/group/ HPDesignJet_Printers: "Interesting stuff. I am going to pass it on to my Cirkut photographer friend who has his own lab in his basement. He feels the minilab has ruined the reputation of chemical prints because they all use washless processes. His prints all include a wash cycle and should have better life than the Fuji Frontier prints. (Wilhelm used to rate the Fuji prints longer (60 years I think) before they all became minilab prints) Also, if the Snapfish prints really are Kodak paper, you can expect a shorter life than a real Fuji Crystal Archive print. What's it say on the back?" To which I responded: "Just looked to confirm, and it does says "Kodak paper" on the back of the Snapfish print. Maybe this (or the processing control) is the reason my test sample is starting to lose ground to the best inkjet ones. Don't know for sure." -- Harald Added Comments: August 13, 2006 Colin Clarke from Hastings, Australia, posted these comments after reading the report on the digital-fineart forum at: http://groups.yahoo.com/group/digital-fineart : "Just got your post on Yahoo DJ Group, Harald. Good technique, but why did you use only blue? On advice from a major industry supplier I too have done some similar comparisons with HP paper and canvas. I used MIS HP replacement ink, HP Vivera ink, and a third party pigment. The pigment was the worst, its yellow going white in three months, and the MIS inks faring much better but going off noticeable in the same time. Magenta also suffered. Blue lasted longest. What the supplier told me to do, (I was looking for a decent display life for canvas prints), was to prepare a known Wilhelm sample, e.g., the HP PPSatin and Vivera, with unknowns all with the same exposure. This way you get a good relative result compared to a known quantity. My results agree with your view, the HP ink and paper was easily the best combination. And I responded: "Thanks Colin. It's not that I chose blue, it's that this is the image I was testing. And it happened to have a lot of blue in it. The next image will be completely different. (As I explain in the report, this is not a standardized test.) I was also interested in testing with one printer (HP 8750) and one inkset (Vivera dye) with a couple of non-inkjet variations thrown in for curiosity. Thanks for your interest!" -- Harald ^ back to top ABOVE: Harald's setup for Window Test A. The actual test print samples are visible on the window, facing out. First Report: April 22, 2006 I just pulled down some inkjet print samples from my South-South-West-facing office window after three months of natural daylight exposure. Here are some interim EYEBALL-ONLY evaluations of VISIBLE FADING to my eye. I wanted to get a feel for what was happening, if anything, before reinstalling them for more exposure. I'll eventually scan and show all the results. WARNING: This is NOT a standardized test for generalization to all prints. In fact, it's the opposite: This is a custom test for ME and THIS image. And although it doesn't look like it, the image does contain C, M, Y, and K. Basis: -- Image: an actual photo that I'm both giving away and selling. This is NOT a standard test image, but a real one I'm actually working with and interested in. -- 8 prints of the same image all printed 4x6" so I could fit them on my window and still have some light coming into the room. See the setup in photo above. -- I covered half the print with tin foil, taping the foil around the three borders. This way, I could evaluate the changes instantly when the foil was removed. Why foil? It's my assumption that the foil reflects the light and heat, while the exposed side absorbs the heat (and speeds up fading). I could actually feel the temperature difference on the backs of the prints with my fingers. The foil is taped pretty tightly so the air flow is probably also reduced, but I'm not sure about that. (see 4/29 added comment below) -- I taped the prints face-out onto some little plastic strips so there would be a gap (about 1/4") between print surface and double-paned window glass (for air circulation over print surface). These were NOT stuck to the glass. -- 6 of the 8 were printed on my HP Photosmart 8750 (dye-based) printer with the on-board HP Vivera inks (and 2 others by other technology, see below). This was the printer I was using for this image, and I wanted to limit the printer variables. I also figured I'd be able to see fading faster with dye vs. pigment inks; I wanted to see the worst. -- I live in central Virginia, USA, and the 3-month test ran from Jan. 15 to April 15, 2006. Because of my latitude, window location, and time of year, I averaged about 5.75 hours of direct sunlight on the prints per day. This will change significantly for the next 3 months as the sun will rise over my house with less time on the prints. -- I didn't control for the Temp or Humidity, but my house is centrally air-conditioned and heated (heat pump), and the temps never varied outside of 66-76 F (roughly 20-25 C). Since this was mostly wintertime, there was more heating going on (more in 66-68-degree range) with resulting dryness. I wanted this to be normal house conditions in my area. I also didn't control for light level (Lux) for the same reason (besides, Lux doesn't tell the whole story; my prints are obviously receiving UV and IR radiation). So Here We Go... after 3 months, judging by my eye only in diffused daylight coming through a window on a cloudy day, in descending order of visible fading (least amount of fading at top) of THIS image: 1. HP 8750 on HP Premium Plus Photo paper, Soft Gloss, 11.5 mil (swellable) -- no visible fade 2a. HP 8750 on Epson ColorLife Semi-Gloss, 10 mil (swellable) -- only a hint of fading 2b. Snapfish online print, I'm guessing Fuji Frontier, on "Kodak paper" (wet chemistry) -- only a hint of fading 3. HP 8750 on Ilford Galerie CLASSIC Pearl, 250gsm (swellable) -- some fading 4. HP 8750 on Ilford Galerie SMOOTH Pearl, 280gsm (microporous) -- some more fading, more than the one above, as expected 5. HP 8750 on Kodak Professional Inkjet Photo Paper, Lustre, 255gsm (microporous) -- clear fading visible 6. Offset lithography, same image printed in my "MDP2" book (page 376) NOTE: only up for 2 months (added late) -- very visibly faded already in 2/3 of the time of the others 7. HP 8750 on HP Glossy Brochure and Flyer Paper, bought at Staples as a cheap alternative, 160gsm (coating, if any, unknown) -- terrible fading My 3-Month Preliminary Fading Observations A. When using these dye-based inks on this specific image, I'd better stick to swellable-coated papers, especially the ones recommended by the manufacturer. In fact, the #1 option above is the only one that has shown NO signs of visible fading so far. I'll see if things change after another three months. B. The wet chemistry print did surprisingly well; will be interesting to see if that holds up after 3 more months. C. Kodak's claim that its Prof. Inkjet Photo Paper is "compatible with dye and pigmented ink printers" certainly doesn't hold up in terms of fading by my test (and that's only after three months!). D. I can probably forget about offset and cheap office-type inkjet papers under these conditions! Future Tests/Evaluations -- I'll consider doing spectro measuring before, during, and after. -- I might measure the temperature and humidity and maybe radiant energy, if I get a data logger and become more ambitious (doubtful). -- I might add some Blue Wools as a dosimeter. -- I might test some sprays/post-coatings. -- I'll probably change printers and papers, and definitely images (with different colors), rotating them around on the window to average out time-of-day shadows and stuff. NOTE: Anyone can do similar self-tests of your prints for a relative comparison of results. It's pretty easy to do; all you need is time and some window space. I'll go into more details next time around and show more pix. I think this is a good down-and-dirty way to see how YOUR prints fare under YOUR daylight display conditions. Added Comments: April 29, 2006 I replaced the prints on the window to resume the test, but I changed their ordering to even out any biases or strange shadows or whatever. I received some good comments and suggestions from people after posting the material above. Here are some thoughts and improvements based on those: -- I improved the foil covers. To make the foil fit even tighter over the covered image portion, I not only retaped them better, bowing the prints a bit to make the foil sit tight against the print, but I also added a little piece of double-sided tape to the open edge to hold the foil closer to the print surface. I admit that all this is a little clunky and will probably discontinue this method on the next round of window tests. -- Another reason I used foil covers vs. putting a duplicate set in the dark is because this image is symmetrical. So covering half of the image is relatively easy to do and makes some sense. Obviously, if the image is non-symmetrical, this approach becomes problematic. -- Some questioned why I used an image with so much blue. As I explain above, this is a real image I'm working with. It's also already printed in a book (at the same size), so that makes a comparison with offset printing very interesting for me. Also, this image actually does contain significant amounts of all four primary printing colors (C, M, Y, K). However, I will probably use a different image with more a more-obvious color range for my next round of tests. -- As to why I'm using double-glazed window glass, that's how my house is built, and I'm not going to change that for the sake of these tests. In fact, virtually all houses in this region of the U.S. and further north have windows like this. Yes, it's true that regular window glass can filter out much of the UV radiation, and in theory two layers of glass might even cut out more UV, but window glass has a UV cut-off at around 330nanometers, and there is still plenty of UV coming in below that level to damage a print. I believe window glass still allows for some serious UV exposure. -- Because the ASTM (www.astm.org) is becoming a more active player in this digital printing testing arena, I may utilize one of their existing test standards (D5398) on my next tests. This standard uses the Blue Wool fading scales for timing the test. The U.S. version of the Blue Wools can be purchased from Talas in New York City at www.talasonline.com for $9.50 each. They call them "Blue Scales." Added Comments: May 1, 2006 Colleague Mark Gottsegen, an artist who also works with the standards-testing organization ASTM International, sent me these comments after reading the report above: Two notes: 1. "Direct sunlight is not necessary. That will accelerate the test, but even just plain old full-spectrum daylight is good enough. A friend and fellow tester's studio is overhung with tree branches and she often has cloudy weather, but she still gets credible results with her D 5398 tests." [HJ: The sun is about to move over my roof soon, so I'll be testing Mark's daylight theory soon enough.] 2. "When I was doing this sort of test, I went to the local hardware store and bought 1/8" thick aluminum to use to cover the Blue Wools and half my samples. Rigid and flat. I also attached my sample panels to a piece of hardboard -- likewise rigid and flat. I clipped the aluminum sheet over the test panel to the hardboard: tight fit and no light leaks under the aluminum to affect the Blue Wools." [HJ: I like his suggestion about the aluminum strips. I was being a bit lazy, saw the tin foil sitting there and thought, why not? The lack of tight fit is the 'why not' I now see.] Mark D. Gottsegen Chair, ASTM D01.57 Associate Professor Department of Art UNC Greensboro -- Harald Johnson ^ back to top (back to Print Permanence index page) Home | About Us | Advertise | Contact Us News & Reviews | How-To's | Resources © 2002-2007 Harald Johnson Communications. All rights reserved.