How do you mount / mat pt/pd prints?

Something I've thought about for a long time is how to safely mount and mat pt/pd prints. If I understand it correctly, the pt/pd process is in an ever so slight acidic pH. Most rag and mounting boards out there have buffers in them of an alkaline nature.
Isn't it counterproductive to put a pt/pd print in such board?

I know pt/pd is a very stable process, but if somebody here has knowledge of how those types of prints fare in that kind of environment, I'd be interested to hear it.

Thanks,

- Thomas

They should be mounted the same way, but archival museum board is better, it's a higher grade than some of the cheap buffered boards.

Ian

hinging or tipped in on archival museum board

Thanks! So what exactly is 'archival museum board'? Cotton rag?

See here, I sometimes use Daler, just depends which wholesaler I go to (I buy from the same places as picture framers) but there are other manufacturers making similar. It's not exactly rag board that's usually a lower quality.

Ian

Hi all,

There is another aspect not much discussed here on APUG, but that I did see referenced in a book by James M. Reilly "Care and identification of 19th century photographic prints", and that is, that the paper support of platinum / palladium pictures, or interleaving sheets of paper, can ironically be degraded by the platinum itself.

So, while the platinum / palladium image and metals themselves are highly stable, the pt/pd metal can act as a catalyst for the discolouration and embrittlement of paper. This seams to be a rather typical issue of pt/pd prints, due to the nature of the used metals. Well, I guess it is not without reason platinum is also used in car exhausts, and other industrial processes. I have included this part of the book as PDF attachment. This process can also cause mirror images on interleaved sheets or backsides of paper if the pt/pd prints are stacked, see the PDF for an image with an example of this.

I don't know if this process affects all paper types. Sure enough, lignin containing / non-wood free cheap papers will be affected first, but is there actually anyone who has read more about this issue and the long term fate of paper supports of pt/pd prints? :confused:

It would be rather ironic and tragic if you had an "eternal" pt/pd print, only our descendants to discover the paper support succumbing to the catalyst activity of the precious metals...

Marco

So the calcium carbonate buffer would have no ill effect on a platinum print? I thought it was this kind of buffer that would sustain the life span of a silver print?

Am I misunderstanding something here? I always read that silver prints need to be mounted and over-matted with materials that are buffered to protect against acid air pollutants.
A platinum print is acid by nature. Wouldn't the buffers, presumably alkaline, affect the pH of the platinum print negatively?

Ian Grant said:

See here, I sometimes use Daler, just depends which wholesaler I go to (I buy from the same places as picture framers) but there are other manufacturers making similar. It's not exactly rag board that's usually a lower quality.

Ian

Click to expand...

Excellent, Marco. Thanks!

Marco B said:

Hi all,

There is another aspect not much discussed here on APUG, but that I did see referenced in a book by James M. Reilly "Care and identification of 19th century photographic prints", and that is, that the paper support of platinum / palladium pictures, or interleaving sheets of paper, can ironically be degraded by the platinum itself.

So, while the platinum / palladium image and metals themselves are highly stable, the pt/pd metal can act as a catalyst for the discolouration and embrittlement of paper. This seams to be a rather typical issue of pt/pd prints, due to the nature of the used metals. Well, I guess it is not without reason platinum is also used in car exhausts, and other industrial processes. I have included this part of the book as PDF attachment. This process can also cause mirror images on interleaved sheets or backsides of paper if the pt/pd prints are stacked, see the PDF for an image with an example of this.

I don't know if this process affects all paper types. Sure enough, lignin containing / non-wood free cheap papers will be affected first, but is there actually anyone who has read more about this issue and the long term fate of paper supports of pt/pd prints? :confused:

It would be rather ironic and tragic if you had an "eternal" pt/pd print, only our descendants to discover the paper support succumbing to the catalyst activity of the precious metals...

Marco

Click to expand...

Thomas Bertilsson said:

A platinum print is acid by nature. Wouldn't the buffers, presumably alkaline, affect the pH of the platinum print negatively?

Click to expand...

The point is, both platinum and palladium are highly stable compounds / metals. They won't easily react themselves and degrade like silver does, so the pH of the paper is probably completely irrelevant to a Pt/Pd image's life. However, the link I pointed out, shows that especially with low grade papers, there is a serious risk of degradation of the paper support by the catalyst activity of the metals. However, this does not affect the metals or pt/pd image themselves in any way, just the paper!

So like Ian suggested, using good quality lignin free matting board and printing paper, is the way to go. And besides, the alkalinity of paper is so low, it is not like you are pouring sodiumhydroxide over your prints

The only type of prints that might suffer from buffered matting board, are potentially cyanotypes, Mike Ware has written about this, but the prussian blue pigment that those images consist of, is vastly more vulnerable than pt/pd can ever be... although it is used in oil paints as well, and can last for centuries in such a stable environment.

I use Light Impressions archival mats. I corner mount the print to the back mount. I hinge mount a mat (again usually 4 ply) to the back mount, the top mat is cut to create a window for the print. I usually cut the window to reveal only the image area of the print, but I occasionally will leave the brushed edges of the print exposed. When the prints are stacked for storage, the image area of the print will not come into contact with the mount of the print stacked on top of it because of the thickness of the window mat. This also is how I display my prints, so it makes it easy to change out prints in frames for hanging on the walls.

I'm wondering if anyone can point me to a good primer, web or book, on mounting, esp. hinge mounting. I need basic step by step instructions with recommendations for archival materials. Something along the lines of Allen Friday's post above, but with complete detail. I'm very new at this aspect of photography.
Are any of you familiar with such a resource?

Thanks.

Thomas, you've confusing process with product. While it's true that the chemical process of Pt/Pd printing works best under somewhat acidic conditions, when finished, you want the paper to end up in a neutral to slightly alkaline state for longevity. The final image is comprised of tiny particles of Pd and/or Pt which are of course very non-reactive and stable ("noble" metals). This image will last as long as the support upon which it's printed. So, a typical work flow might include an acid pre-treatment of the paper to remove any buffering compounds (oxalic acid is my preference). You also want to keep your potassium oxalate developer in an acidic state (pH 5 to 6 is good) which is accomplished by adding small amounts of oxalic acid as necessary. For most papers, post-development clearing works best by placing the print first in an acidic solution such as citric acid, then two successive baths of regular working strength Hypclear or Permawash, each for roughly 5 minutes. A final 15 minute wash should be sufficient. You should not rinse the print with tap water between the development and clearing steps unless you are certain your tap water is not alkaline. An alkaline rinse immediately following development can make subsequent clearing very difficult. Stuart Melvin and Clay Harmon both have experienced this effect. My water comes out of the tap at about pH 6.5. I believe Clay also found longer development times helped him with clearing issues. I usually develop for about a minute (developing longer has no real effect on the look of the image).

I use Rising Warm White acid-free matboard and corner mount my prints. I often cut the mat right up to the image, but sometimes not.

Thanks everybody for the clarification. One more barrier to my dream of making pt/pd prints in the future has been removed.

It appears I have a lot to learn, which is good, because for the foreseeable future I won't have the money to invest in the equipment needed anyway.

- Thomas

I second Allen Friday's technique. I have used Light Impression's Westminster Rag Board for both silver and PT/PD prints for years. Mount with their ClearHold corners. I haven't had any problems. In the event that a mat is damaged or you wish to change the mat size the print just slips out.
Jeffreyg