Confused about Buffering - Mats and Papers

Started Feb 1, 2009 | Discussions
SantaFeBill Senior Member • Posts: 2,501
Confused about Buffering - Mats and Papers

Both Light Impressions and answers to a post about the topic said to use non-buffered mats for mounting inkjet prints.

But I'm noticing that some fine arts papers specifically mention that they are buffered, e.g. some of the Canson ones and also some from other vendors.

So, why should you use non-buffered mats but use buffered papers? Seems contradictory.
Does 'buffered' mean something different in each case?

colourgeek
colourgeek Veteran Member • Posts: 3,577
Re: Confused about Buffering - Mats and Papers

You are right. This is a wuestion that seems to go unanswered.

I went out and bought pH neutral acid free tapes, buy premium papers cotton rag, no OBA, yet the supplies of mounting materials and those who care enough to respect the notion of non buffered pH neutral ( well a little on the basic side is fine too as most of the rag papers are slightly basic) are few and far between.

All I know for sure that in an ideal situation non buffered mounting materials with high quality base materials will fetch the highest permanence by far.

PS the buffering in the papers I know, are actually just a control situation necessary for production. They are never used to cancel out poor technique, poor washing , simply to adjust the flow to spec. When they say buffered for mounting stuff it is definitely canceling out a process or material characteristic.

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Neil Snape photographer Paris printer reviews at http://www.neilsnape.com

Mark McCormick Senior Member • Posts: 1,094
Re: Confused about Buffering - Mats and Papers

SantaFeBill wrote:

Both Light Impressions and answers to a post about the topic said to
use non-buffered mats for mounting inkjet prints.

Many dyes are actually more stable in a slightly acidic environment. Inkjet receiver layers designed to help stabilize dye-based inks are often slightly acidic. While we've all been told over and over that acid should be avoided at all times, the simple fact is that some color photographic prints with a reputation for longevity do in fact rely on a slightly acidic image receiver layer. I'm thinking especially of Kodak Dye transfer prints which have an excellent reputation for image permanence in the museum world.

For pigmented inks, the buffered versus non buffered question is a rather academic discussion, as the pigment particles are not going to migrate from acid to base conditions which is what can possibly happen (under high humidity conditions) when acidified dyes come in direct contact with an alkaline buffered tissue or mount board. Buffering agents in rag board are typically materials like calcium carbonate. While buffered mat board can protect against "acid burn" from external polluting sources (No3 and SO2 gases from urban smog, etc), it won't stabilize wood pulp papers with lignin remaining in the bulk material, etc. I've seen many "archival" mat boards that don't live up to their marketing hype. Stick with reputable manufacturers of mat board and papers, and consider the non-buffered materials if you are matting and storing dye-based inkjet materials. Otherwise, either buffered or non-buffered will be OK provided, as Neil also noted, the inherent processing during manufacture was done well.

Mark
http://www.aardenburg-imaging.com

SantaFeBill OP Senior Member • Posts: 2,501
Re: Thanks for two very informative replies. (nt)
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SantaFeBill

colourgeek
colourgeek Veteran Member • Posts: 3,577
Re: Confused about Buffering - Mats and Papers

Excellent answer MarK.

I was just thinking about the pH of the papers I have, and I just checked , most are 8-8.5 pH, but I remember some numbers on the acidic side around 6.6. These must have been the papers swellable polymer papers and perhaps some of the instant dry. Hence your explanation that the dyes live better in an acidic environment proof that when the media are developed there are quality decisions compromises to be made.
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Neil Snape photographer Paris printer reviews at http://www.neilsnape.com

Bedlam Forum Member • Posts: 50
Re: Confused about Buffering - Mats and Papers

There seams to be a bit of confusion about the buffered/non-buffered question. Not surprising since in the matting industry it is often not explained well. Its must like the term "acid-free".

When the term buffered is used, it could be referring to inexpensive Buffered mat board. This is paper matting that contains all the natural acids and lignins found in wood pulp and is treated with calcium carbonate to create a Ph neutral state at the time of production. The mats are a decorative product only and often la baled at "Buffered Acid-Free" and should not be confused with true acid free matting. Over time, the acids over power the buffering and will do their damage.

Matting made from alpha-cellulose which is the purified part of wood based papers contains no acids or lignins and is considered a conservation grade by most standards.

The next levels are combination's of alpha fibers and cotton and pure cotton for the highest museum grade matting. All of these mat board products regardless of being conservation or museum grade rag will also be buffered. The only exceptions are some museum rag. The question of buffered vs un-buffered comes down to the materials being matted. Un-buffered for any animal based print such as silk, and buffered for plant based; basically most everything else.

Outside of the decorative buffered mats which should not be confused with true acid free matting, nearly all mat board will still have a level of buffering on top of being pure of any harmful materials; lignins and acids.

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