Buffered or Un-buffered Matts

[Kirk Gittings]

Jon Shiu asked a question related to this on another forum. I moved this question from the other thread to get some broader feedback.

According to Light Impressions, you should use un-buffered mats on all "color" materials. They say use buffered for all b&w materials, but they may mean just silver or PP for b&w.

I use buffered for silver prints and non-buffered for all ink prints. Any other research and recomendations out there?

[Doug Dolde]

Library of Congress Guide to Preservation Matting and Framing

http://www.loc.gov/preserv/care/mat.html

[Michael Graves]

I use light impressions board for those incredibly rare prints that I get that are worth mounting. One thing that LI sells that I kind of like; but didn't see mentioned in the LOC article was those clear plastic sleeves for storing matted prints. LI claims that they are archival. Anybody else use these?

Or should I really care, seeing as how, according to the other thread on our legacy my kids are going to throw out all my old photo junk anyway?

[Bruce Watson]

According to Light Impressions, you should use un-buffered mats on all "color" materials. They say use buffered for all b&w materials, but they may mean just silver or PP for b&w.

The pH in buffered boards is higher than neutral. The theory is that this somewhat alkaline pH will effect the chemistry of a "C print" and cause it to color shift and/or fade. Whether it will or not is probably a variable depending on the technology of the C print.

This does not, AFAIK, apply to pigment inkjet prints. The pigments are mostly impervious. The papers, however, are not. Mostly the papers are unbuffered water color papers. Very absorbent, especially of atmospheric pollution which tends to push the papers' pH toward the acidic side. This in turn damages the paper (not necessarily the pigments). If this is true, one would think that using a buffered board is the correct play with pigment inkjet prints.

I've been using buffered boards for the last four years with my pigment ink prints. Mostly Superior Archival Materials' ArtCare matte boards. So at least I'm putting my money where my mouth is ;-). So far, no change in either prints or matting, even of framed prints that see significant direct sunlight every day. We'll see in another couple of decades if I did the right thing...

[Kirk Gittings]

So the acid in the unbuffered board tends to yellow the paper base? Interesting. That would make my life simpler as then I could use buffered board for everything.

Have you ever compared the cost of Superiors products to LI? How do they compare?

[JW Dewdney]

So the acid in the unbuffered board tends to yellow the paper base? Interesting. That would make my life simpler as then I could use buffered board for everything.

No - I'd have to say that is absolutely NOT true. There is no acid in normal museum-grade cotton rag board. It's simply that the calcium carbonate added to BUFFERED board makes the effective pH of the board higher. I'd be willing to speculate that the reason it's NOT recommended for color work or inkjet work is simply that you will notice deterioration in the middle of the image before the edges (by dint of the effect of the buffered board), not so much that the alkali will affect the artwork adversely.

[BrianShaw]

There is some information on this topic published at http://www.wilhelm-research.com/

See the permanance and care book link, Chapter 12 and 13... possibly others

[Jon Shiu]

I've been using the regular LI Westminster buffered board (pH 9.0 +/- .5)for inkjet prints for the last two years. I noticed that sometimes the inkjet art papers have a buffered core and have a slightly higher than neutral pH, such as 8.5. I hope I don't have to replace any of the prints I have sold.

Jon

[Bruce Watson]

So the acid in the unbuffered board tends to yellow the paper base? Interesting. That would make my life simpler as then I could use buffered board for everything.

No. An unbuffered board will be neutral, not acid.

It's the acids in the atmosphere that are the problem. What a buffered backing board does is impede the advance of the acids. If the board is neutral, it doesn't take much exposure to the acids in the atmosphere to make it acidic, then it begins to break down an therefore becomes even more acidic, and since it's in contact with the print... You get the idea. A buffered board acts as a buffer between the print and the atmosphere.

[Michael Daily]

There is some information on this topic published at http://www.wilhelm-research.com/

See the permanance and care book link, Chapter 12 and 13... possibly others

Light Impressions follows Henry's guidelines. As I remember, Henry was involved in the Start-up of Light Impressions while he was with the co-op East Street Gallery in the early 70s.
Michael