significant Hahnemuhle Photo Rag paper Problem

I am a book and paper conservator. I have recently been informed of a problem

with the paper. Apparently during a printing and binding process it was found

that the paper was yellowing after the pages were stacked for a period. The

yellowing occurred overall in strips and around edges. After research the

conservator gave the following information:

 

* The Optical brightening agents are causing this effect

 

* The OBA's alter the reflection of ultraviolet light in such

a way as to make the paper appear cooler white

 

* The yellowing occurs in paper which is stacked or contained

(apparently it has to do with out-gassing)

 

* exposure to light and air will get rid of the yellowing

 

I thought this info should be given to photographers.

Thank you for the update,wow, I'm disappointed in this, I have some of this very type of paper in a sample pack that I plan to use. I am an amateur photographer with an Epson R3800 pigment printer. I may give more thought to ordering any future papers to be those with no OBAs, which probably will be more expensive(than those with OBAs).

Thank you, Debra

So I guess the best thing to do is simply display the work! Good info to know tho, and another observation that Wilhelm apparently doesn't cover? I wonder what the long term consequences are?

 

On another note, I remember quite a while back a Photo Techniques article on silvering out of B&W prints on display. That was interesting.

I'm guessing that Wilhlem's protocol doesn't include stacking or sealing sheets together relatively air-tight. They use tests that basically approximate time and exposure. While these tests are very useful, they don't tell the whole or complete story. Age testing in a chamber at 100 degrees is not the same as actual "time" and long term exposure is different than short time, it's a best guess approximation.

If prints are allowed to breath, to some extant, I doubt that one will have to deal with the problem. But if one is printing for binding, or sealing matted shots in plastic than it's a factor.

Dear Bruce,

 

More info, please?

 

If true this is bad news, because HPR is one of the best-looking & most widely used fine-

art photo papers. The photographer-artists who use it believe they're making 'archival'

prints - in spite of the fact that HPR contains a moderate dose of OBAs. The papers that

have none at all, for example Epson's Ultrasmooth, don't look very good in comparison -

as if they'd already yellowed.

 

Out-gassing is a known problem with glossy & luster papers, but it's not a generally

acknowledged problem when a matte print on 100% rag has been allowed to air-dry for

24 hours.

 

We don't normally stack prints on HPR, nor bind them. They're usually stored 'archivally,'

without exposure to light, until they make their way into frames. Then they meet up with

a 100% rag overmat & undermat, & with limited protection under glass or plexi. If they

aren't going to be framed soon, then after their day of drying they go into clear plastic

bags, which in turn go into storage boxes. The bags & boxes are marketed as 'archival' or

PAT materials.

 

 

Could you - or your source, the conservator - give us more information about the

conditions under which something went wrong on HPR? If, for example, the prints had

been stacked right after they were printed, that's just human error, not a problem with the

paper.

 

Kirk

Hi Kirk,

 

I think as long as the surface is able to breath there won't be a significant problem. With plastic bagging I would make sure there is an air outlet, even if you have to make a slit along the flap edge. A few years ago when paper conservators encapsulated objects it was found that the object "stewed" in it's own degradation products when sealed on all sides. Now one usually leaves a side open to allow for off gassing. You might want to consider using a folded piece of archival mylar or mylar sleeves instead of plastic bags. The mylar is inert and allows free passage of air. Look at the offerings at either Light Impressions or TALAS.

Also, the archival properties were not fully addressed in the notice. While the yellowing "looks" like acidic deterioration, it may be that the discoloration is relatively harmless, chemically (but I'm not sure). Still, the visual aspect of the problem is bad enough.

Hi, Bruce -

 

Right - and most folks don't seal the bags; but that's not really the point:

 

The info is still pretty vague, & I wish you'd clarify. Where's the 'notice'? Have you seen

the case in point & do you now how the paper was used, stacked, etc? Which version of

HPR was it - single-sided HPR, coated on one side; or HPR Duo with images that would be

bound as facing pages (that is, with the coatings facing one another)? It's really hard to

tell if 'the notice' points to a real problem for photographers, given the way they usually

handle & store their images.

It was on a conservation DistList out of Stanford U, it's called CooL (Conservation online) and is published by Walter Henry. The paper used for the book was uncoated HPR with the OBA's. They used the uncoated, to my understanding, because of the folding necessary for binding. It was folded and stacked and put aside for later binding. I dumped the original post, but here's the main page. It says the search function is temporarily down but will be back up soon.

http://palimpsest.stanford.edu/

"It's really hard to tell if 'the notice' points to a real problem for photographers, given the way they usually handle & store their images."

 

That's my point, but as I said, I think it's something one should know about.

I'm not an expert, but I'll ask a couple obvious questions, since I didn't see them asked/mentioned and it is taking me a while, personally, to figure out the difference among papers that seem somewhat similar....

 

Did you (or the conservator) use the PhotoRag 'bright white' paper with OBOs to give it a brighter white...it will list this on the box (or plastic pack)? If so, that would be what's causing your reported obo issue, and you might try the one that just says "photo rag".... Otherwise, I have stacked photo rag duo inket duo prints together (unbound, but pressed together w/out interleaving material) in a print box for a couple years and I haven't noticed any yellowing of edges yet. You might also want to check (if it isn't the "bright white" version that is causing your reported obo issue) about the relative archivalness of the binding/cover.

 

You may want to try the whitened one also. You may find that works better for you.... Under certain light the photo rag looks like it's yellowing under tungsten light out of the box compared to papers without obos, which is not decay. Non brightened paper fully exposed to the elements may appear to yellow faster (esp. for smokers) as it starts out less pure white (just a guess).

 

It kind of sounds like the same old issues that darkrom people describe about emulsiions with and w/out brighters.

 

I'd email hahnemuhle for suggestions also, because it it's an issue, they will have likely encountered it and may offer some alternative choices in their line....

I just looked it up on their site. Hahnemuhle has obo free versions of photo rag, so I'd stick with these papers if it's an obo issue.