Rag or alphacellulose

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mrs.fidget

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I am putting together a plan for preservation of a clients artwork. I'm not sure which is considered better Bainbridge alphacellulose matting with its zeolites or rag boards. ?? Zeolites eat upt baddies and traditionally rag is the museum standard. Which would you recommend. Client has oil pastels and watercolours.
 
Bainbridge Alpharag with zeolites?

Actually, buffered alphacellulose is conservationaly equivalent to RAG. Tradition is generated because of conditions in the past not the present or future.
 
Its matrimonial, but I would lean towards the Zeolite, only because I've used the stuff for years. (the mineral Zeolite, and the boards)
 
Why not use Alpharag Artcare - 100% cotton rag that incorporates the MicroChamber zeolite technology. Specs for reference.
 
You may want to look at this short thread as well. It refers to buffered mats and photos but may be of interest:

http://www.thegrumble.com/showthread.php?t=45361&highlight=buffered+mats

Obtaining unbuffered mats seems to be problematic for some.

Rob mentioned on this thread
It is pretty easy to tell an "old print." The question is, is an inkjet print "contemporary color material" or were the guidelines written before a significant number of contemporary prints were digitally output using inkjet technology?

So what about ink jet prints? Any further thoughts on this, anyone?
 
This is a serious question-

Can someone explain to me why a RAG board is "superior" to virgin alpha-cellulose board? I am talking from a "technical" perspective, not an aesthetic one. This is a "suitability" question.

If both boards are:

neutral pH and buffered with CaCo2 to have an alkaline reserve

are fade and bleed resistant

alum and lignin free

both contain zeolites

How can one say that Rag is a superior? How would one be "more appropriate"?

The only criteria I can see for a board to me more or less appropriate for a specific preservation use is if it is buffered or not and of the appropriate thickness, not what it is made from (if it meets the other criteria above.)

I have a hard time understanding how one could be considered superior to the other. At one time, cotton linters (rag) was the only material that was lignin-free (naturally) and it made a superior board.

And, for those of you who have been framing long enough, there was a major matboard manufacturer who did not have an alpha-cellulose product (only had rag) and in their marketing, they perpetuated the "superiority" of rag.

Then, they came out with their own line of alpha-cellulose boards - and sort of changed their tune :). But, with the advent of modern manufacturing, virgin alpha-cellulose meets all of the criteria for preservation so the "superiority" of rag becomes moot.

So getting back to the OP's question - why would Alpha-Rag be the "best of both worlds" and any more appropriate for the framing/preservation of pastels and watercolours than Alpha-mat? Personally I think that the hinging, booking of the window mat to the backing of the art and the choice of mount board would play as critical a role and I am surprised that this part of the equation was not called into question.

Thoughts?
 
There's wood alpha cellulose and there's cotton or 'rag' alpha cellulose - they're both alpha cellulose - the wood alpha cellulose just took longer to process.
 
Robo-

So your point is.....?
 
There is no difference in the level of protection.

Having said that some suppliers'/manufacturers' claims/tech-spec can be misleading so cotton can be a safer option if in doubt.

Regards artcare, I only stock alpharag for the look of the solid core and being more French-mat-friendly than the 'vellums' which are inconsistent.
 
No argument here Rob. I tend toward the zeolites technology but since the Artique alpha cellulose boards came out in solid color 8-ply, economy has pushed me in that direction. I figure an ArtCare mount (either Artcare Alphamat or Artcare Alphamount which I believe is cotton) and ArtCare foam board support would serve the purpose for proactive preservation.
 
By definition, alpha cellulose is the highest grade of cellulose; purified pulp with contaminants processed out. It may produced from cotton linters, trees, jute, and other fibers. For the purposes of preservation framing chemistry, alpha cellulose is alpha cellulose, no matter how it originated.

The only real difference between cotton alpha cellulose and wood pulp alpha cellulose is in the length of the fibers. Cotton fibers are cleaner to begin with, and require less processing than pulp made from wood. In manufacturing paper, less processing results in longer fibers; more processing results in shorter fibers.

So, cotton boards are generally softer, more cloth-like, and have a slightly more "toothy" surface texture, which may be helpful in holding the fibers of paper and textile in an overlay mount, for example.

Boards made from wood-pulp-based alpha cellulose are generally heavier, more dense, have a harder surface, and cut more crisply.

Some framers claim one type of board is better than another for applied decorations, such as painted panels, watercolor washes, and pen lines. However, that has more to do with surface sizing than fiber type.

When a framer claims one type of alpha cellulose board is better than another, he's stating his opinion, not a fact.
 
Jim Miller said:
When a framer claims one type of board is better than another, he's stating his opinion, not a fact.
Click to expand...

Yes, and this has always been my opinion, reinforced by your excellent articles. But what about the use of buffered mats on both antique and digital photographs?
 
But what about the use of buffered mats on both antique and digital photographs?
Click to expand...

That's an interesting question, Kirstie. As far as I know, no functionally adequate answer has come along yet.

We know that in a closed-up frame package, the high-alkaline buffer in most boards could react with some alkaline-sensitive items. Trouble is, probably the majority of us are not qualified to determine what items are alkaline-sensitive, other than some organic items.

When I have asked, a couple of conservators have pointed out that most framing projects do not require the use of buffered boards. By their line of thinking, we ought to create a micro-environment as close to pH neutral as possible (that is, using unbuffered materials) unless we know there is some reason to create a micro-environment that is either alkaline or acidic.

These conservators have also said the same is true of zeolite additives; that they serve no purpose in a closed-up frame that does not benefit from the additive. However, the word I've heard is that the zeolite additive poses no risk in framing -- unlike the high-alkaline buffer.

I'm no scientist, so all of this from me is hear-say. I don't know enough about chemistry to use the information intelligently, and I doubt most other framers do. Maybe Hugh, Rebecca, and others more knowledgeable will give us better information.
 
Legion/Rising matboards are available in three varieties:
A. 100% cotton "Museum" boards, buffered
B. Alpha cellulose "Conservation" boards, buffered
C. 100% cotton "Photomount" boards, un-buffered

This is a direct quote from the Legion paper web site:

Buffering
All Rising boards are buffered with a minimum 3% calcium carbonate (except the Photomount papers, which have no calcium carbonate buffering) as required by the U.S. Library of Congress to protect the board from hostile environmental factors.
Click to expand...
 
From Nielsen Bainbridge - their schedule of conservation attributes for high alpha cellulose virgin bleached kraft or virgin cotton rag. i.e. they are expressing no tangible difference between the two in terms of conservation attributes.

nb.jpg

Going back to the original question in this thread however, if the client displays a preference for rag (for either aesthetic or traditionalist reasons) it would seem commercially prudent to quote Alpharag.
 
Here are a couple of web sites that add some weight to the subject:
http://artfacts.org/standards/expmmb_2000.html
http:www.loc.gov/preserv/care/mat.html

Some years ago I had my daughter gather up 2" wide strips of all different types of matboard used in our shop. She cut these sstrips both with and across the grain. She dried them out in our heat/vacuum press untill they were crispy dry. She made a cut on each sample at 29 inches with a razor blade.

She then layed them oout in big plastic bags with a sopping wet sponge included. The next day she measure again and put another cut at 29".

The most notable difference was that rag based boards expanded almost 3/16 inch from crispy to soggy whereas woood pulp based boards only expanded about 1/16 inch.

So... If you are framing something in Las Vegas (dry) that's going to Jackson MS (soggy) you might want to leave a more generous allowance. And... If you staple or otherwise attach matboard of any ilk to the back of a frame so as to hinder the free expansion and contraction, you can count on it buckling.
 
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