Thanks for the discussion. I always use UV protected glass. I also dry mount all my photos that I sell. So museum standards aren't my concern as they might object to the mounting - I want a print that will maintain the image quality it has when I deliver it. No yellowing or fading for at least 75 years.
I print up to 24x16 myself but use a printer in Boston for larger prints. They use the hahnemuhle photo silk baryta and the photo rag baryta. I'm not not familiar with the second paper but have used sold prints using the photo silk baryta before. I was alarmed to read that article.
Anything I sell is professionally framed.
I'm not a scientist - Mark are you saying the photo silk baryta is going to yellow or fade?
Hi Sharon,
When Ilford went into bankruptcy a few years back, dealer inventories of the popular paper Ifford Gold Fiber Silk began to dry up, and with uncertainty at the time whether IGFS would ever be produced again, other paper companies stepped in to fill the IGFS market gap with more IGFS "look-alikes". Hahnemuhle was one of those companies, and undoubtedly added "silk" into the Photo Silk Baryta name in order to help customers draw a subtle IGFS connection to the newer Photo Silk Baryta. As Ernst has alluded to, where the base sheet papers get coated is a fairly well known fact in this industry, and those coatings tend to dictate the main print quality characteristics and physical surface properties of the paper. Identically coated papers can get rebranded so as to create an undocumented family of "dead-ringers" in the market today. However, without actual testing, one can't be certain that some minor customer-requested production variations at the coating facility won't affect light fade resistance or other permanence properties of the product. Photo Silk Baryta does have some OBA content, but likely no more than HN Fineart Pearl, for example, and FineArt Pearl also has an a-cellulose paper base like Photo Silk Baryta rather than a cotton base. Hence, Hahnemuhle's description of Photo Silk Baryta in its published product sheet is indeed curious, and it may be more about product positioning in the Hahnemuhle "Photo" versus "FineArt" media lines, rather than based on any actual print permanence tests. Regrettably, Aardenburg Imaging has not yet tested HN Photo Silk baryta, so I can't give you specific guidance, but as Ernst suggested, you may want to take a look at the Aardenburg database for older samples of the IGFS and also samples of Canson Infinity Baryta Photographique (another IGFS look-alike). All other things being equal, Photo Silk Baryta would probably achieve comparable scores.
Now for a quick primer on using the Aardenburg-database
. Sharon, you have asked for "No yellowing or fading for at least 75 years" as your personal print longevity figure of merit, and I assume you are talking about continuous indoor display environment, not dark storage conditions. That's a great place to begin defining your own personal print longevity expectations, and indeed there are many printer/ink/media combinations that will meet your stated goal. That said, your goal is also highly dependent on your print buyer's environmental conditions, notably the anticipated average daily light levels on display. So, here's a quick lighting guideline to translate Aardenburg Megalux hour ratings into your desired "75 years on display" :
150 Megalux hours = 75 years of display at 450 lux for 12 hours per day (450 lux is the Wilhelm Imaging Research assumption for consumer light level on display)
75 Megalux hours = 75 years of display at 225 lux for 12 hours per day (relatively bright indoor conditioin)
40 Megalux hours = 75 years of display at 120 lux for 12 hours per day (kodak claimed 90% of all indoor home display conditions are at 120 lux or less, but that leaves 10% of home display locations at higher levels)
8.5 Megalux hours = 75 years of display at 50 lux for 12 hours per day (essentially, museum lighting conditions, rigorously adhered to for objects with low to moderate light fade resistance such as dye-based color photographs. Museums also routinely limit display time to manage and conserve print quality for many generations).
The Aardenburg database lists many printer/ink/media combination that achieve scores greater than 8.5, 40, and 75 megalux hours in test, and even some that reach 150 megalux hour ratings. 75 years with little or no noticeable fading is thus readily attainable, but the caveat, and it's a big one, is that the lower the megalux hour rating, the lower the average daily illumnation levels must be in the display location in order to meet your 75 year print life objective.
Tip #1: for home display conditions, the 225 lux level assumption accounts for about 97% of all locations inside a typical home, and the mental math becomes trivial, ie. Aardenburg's megalux hour ratings = years on display for little or no noticeable light-induced yellowing or fading (your desired outcome). Nevertheless, Aardenburg doesn't routinely extrapolate its print permanence ratings to just one assumed interior light level due to the extremely high real world variations found even with in one home, let alone all indoor locations. I always encourage the print owner to make a more informed choice about where the print will be displayed, and for printmakers to initiate that discussion with their clients rather than merely quote oversimplified one-size-fits-all print life ratings.
Tip # 2: noticeable fade is also image content dependent, hence Aardenburg provides a megalux hour range to encompass both weakest color and tone performance that may or may not be present in a printed image as well as average print color and tone response. However, by sorting the database on the
lower conservation display rating limit("lower CDR" in the database filter menu) you will be guaranteeing little or no noticeable fade for all of your images up to that accumulated exposure dose over time. The reported megalux hour values also correlate with natural daylight illumination entering an indoor enviroment and with the print protected by standard acrylic glazing. UV-block museum glazing can in some situations (but not all) add an additional measure of fade protection. Also, the Aardenburg lower CDR limit is often influenced by media yellowing issues (e.g., OBA burnout and/or additional yellow stain formation), and therefore the lower CDR value is a particularly important rating to consider when trying to choose media wisely.
Tip #3: By using the Aardenburg database filter menu you can narrow your search for printer/ink/media candidates that meet your 75 year expectation at some corresponding illumination level you think is reasonable to assume for your buyer's display location. For example, enter 75 in the "from" field of the "Lower CDR" menu item. The Aardenburg database will return tested printer/ink/media/coating combinations that will meet your little or no noticeable fade for 75 megalux hours of accumulated exposure dose. In turn, that 75 megalux hour rating will satisfy your 75 years print longevity expectation in any display illumination environment of 225 lux or less for 12 hours per day. Add additional filters to narrow the search further, for example, "no coating" in the coating field, to find only samples that had no additional coatings, check box "color" to restrict found samples to color rather than B&W images which in many cases outlast color images due to restricted or specialized use of more stable pigments, etc.
Lastly, one of several unique aspects of the Aardenburg light fade testing protocol is that our Conservation display ratings (expressed in megalux hours) are indeed based on a curatorial expectation of
"little or no noticeable fade", pretty much what Sharon has defined as her expectation for the retention of print quality over the total period of time the print will be on display. "Little" compared to "no" fade opens the test scores up to very small colorimetric changes that can be measured by instrumentation and might be just barely noticeable under a side-by-side close scrutiny with an unfaded control print, but this instrument-measureable amount of fade is not visually discernible in a single-stimulus viewing environment, i.e., no unfaded control print is available for direct comparison. In other words, little or no fade means the print is going to still be in excellent condition at the accumulated megalux hour exposure dose reported by the Conservation display rating, exactly what Sharon wants to achieve
This goal is in stark contrast to other industry-sponsored print display life ratings that allow for "easily noticeable fade" and also misrate products due to obsolete testing methods. Pretty much everyone can closely agree on what constitutes little or no noticeable fade, but once the allowable fading criteria is relaxed to "easily noticeable fade" it becomes a slippery slope. How much fade is too much fade, in other words, when is noticeable fade acceptable versus unacceptable to the print owner? By confining the test scores to the period of print quality excellence where no visible fading is perceived by the viewer, the scores have consistent meaning for both professionals and amateurs alike.
Hopefully, the tips I provided above will help folks to explore the Aardenburg light fade database and better answer their own personal expectations about light fade resistance of prints on display. The database filter isn't as entirely user-friendly as I would like, but with a little experimentation and practice using it, it gets easier to make queries to the database. I also hope this discussion gives some insight on the value of a thoroughly modern, standardized, and instrumented testing protocol combined with an accurate color and tonal image appearance model (the I* metric) which is necessary to objectively quantify not just when prints fades but more importantly how they fade. I do wish we could test many more systems in order to build a far more comprehensive database for today's modern media. However, without more support from the printmaking community and/or manufacturers stepping up to bring their own testing methods and print quality criteria more in line with how we test at Aardenburg, it's as good as it gets for now.
cheers,
Mark
http://www.aardenburg-imaging.com
