Baryta budget alternative

Started 3 months ago | Discussions thread
Mark McCormick Senior Member • Posts: 1,534
Re: A suggestion
2

mike earussi wrote:

OBAs fade and turn yellow over time if exposed to UV light. This is not a problem if your photo is not exposed to either sunlight (directly or indirectly) or to fluorescent light or is framed behind UV blocking glass. The common LED light used today has little if any UV light.

Although eliminating UV radiation on display reduces fading typically by 2-4x the blue wavelength region is still potent enough to cause fading over time. It's still an exposure dose issue with respect to light induced fading and discoloration of prints on display.

All (yes, all) resin coated (RC) media on the market today contain both Ti02 and OBAs in various coating layers. The proximity and concentration of these components results in light induced low intensity staining/yellowing (LILIS) which is worse than just OBA fading by itself. Both the media manufacturers and their consumers seem to be little aware of this issue because it requires an extended light fade testing protocol to identify how much the product will be affected by LILIS. A typical light fade test where measurements are made immediately after exposure misses the problem.

I have identified only three RC media to date that exhibit significantly less (but are not free of) LILIS. One is Epson Proofing Paper White Semimatte. The others are HP Universal Instant-dry Satin Photo Paper and HP Universal Instant-dry Gloss Photo Paper. These media confine the OBAs to the paper-core and keep it out of the resin coated/TiO2 pigmented coatings which make RC photo paper RC photo paper. But there's still some interaction between the TiO2 and OBAs at that coating/base interface, so some residual LILIS still happens, but its far less noticeable compared to RC media where the OBAs are also incorporated directly into the RC/TiO2 layer as well.

Epson Proofing Paper White Semimatte has an interesting semi matte surface which can appeal to many photographers, IMHO, but this media is a little on the thin side (about 9 mil) and only available in roll format or Super B (13x19") sheet size, thus making it less widely available for the inkjet photo market.

"HP universal Instant-dry" photo paper is only available in rolls AFAIK, and is also in the 9 mil thickness range so if feels a little more like an economy photo paper, but at least the two surfaces are more typical satin and glossy finishes that photographers seem to prefer. Also note that HP's nomenclature is very confusing. For example, HP also offers "HP universal" papers and "HP Premium Instant-dry" papers but they are not the same formulation as the two "HP universal instant dry" photo papers which I'm referring to above. The "premium" stuff is only premium because it is thicker, but it's also loaded with OBAs in the RC/TiO2. The "universal" stuff is thinner and bluer-white also due to loading of OBAs in the RC/TiO2 layer.

It would be very easy for the manufacturers to offer photographers an OBA-free version of RC media, and that would improve light fade resistance of RC photo papers dramatically, but as long as consumers aren't demanding it (probably because they are unaware of the issue), the manufacturers will continue to have no incentive to improve the product. Ironically, we do now see the LILIS problem manifesting in real world display conditions, but it's showing up mostly in traditional wet processed RC media because those prints are now older, yet the yellowing is being attributed to bad processing when some of it is simply the light induced yellowing issue in the RC layers. It takes approximately 10-20 megalux hour light exposure dose on display (a couple of decades on continuous display for many typical home display situations) for the yellowing to manifest and since the majority of RC prints end up in shoe boxes or photo albums, it's tricky to assess the "archival worthiness" of RC photo papers. They can indeed last a long time in good to excellent condition if care is taken to protect them from long term continuous display environments.

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