Preservation Beat

Wednesday, August 26, 2009

     A UI prof and grad student were interested in getting a digital copy of Cursus Literaturae Sinicae, a 19th C. translation of classical Chinese texts into Latin in five volumes.  When the volumes came via ILL from Notre Dame, they were scanned using the overhead scanner with the gradation curve set to give as white a background as possible, since it was determined that we should also print out a copy of the scans and bind them for our own circulating collection.  Here’s what they look like.

     The sheets from the printer were perfect bound with the double fan press.  To account for the swelling in such large volumes we decided the backs should be rounded, which was accomplished with the aid of a couple of cardboard map tubes at the fore edge.

 

         

For the first volume (at left above) only three spine linings were used: kozo, acrylic/cotton super, paper.  As this volume had a lot of throw up, subsequent volumes got additional linings: kozo/cotton super/paper/cotton/paper, which worked better.  Hopefully they will stand up well to frequent use.

Monday, August 3, 2009

Ongoing efforts to clean and flatten flood-affected archives manuscripts from the African American Museum of Iowa have turned up yet another form of adherograph deterioration. (See June 30, 2009 entry)

As seen in the example to the left, the powder medium that holds the adherograph text image has irreversibly adhered to the back of a preceding document page.  Unable to separate the two, I decided to scan both pieces of the damaged document and then attempt to reunite them in Photoshop.

The first step was to flip the fragment horizontally.  Though only the back of the reversed fragment text was visible through the adherograph medium, flipping it over digitally created a faint, though workable positive. 

Note the altered color of the reunited fragment.  Through a haphazard process of tweaking color levels and saturations I was able to pull the text out, making it as legible as possible.  After doing so, reducing the image from color to black and white serves to isolate the information from the discolored document carrier.

 This detail, captured after converting document to black and white, shows that while the texture of the adherograph medium remains cumbersome, the information is again legible. 

This second example details another completed document as well as its original post-flood condition.  While this process is probably too time consuming in many situations, experimenting with the procedure was a valuable experience.  Not only is there now a workflow for this in the future, but it also raises some interesting questions about disaster recovery, institutional resources, and policies pertaining to discarding and reformatting.

Thursday, July 16, 2009

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We have been experimenting with a fancy new vacuum packer, generally used for food preservation. We are using it to flatten books and other paper items. It would be inefficient for batch work because of all the material that needs to be cut to size but for especially warped books it is very effective. 

We cut blotter pieces, card, and book board all to size.  All of the interleaving material must be cut to the size of the book so that the edges don’t interfere with the sealing of the bag. The inside of the book is lightly misted, and the blotter sheets placed inside.  The book is sandwiched between pieces of blotter, card, and book board.  Rubber bands hold the stack together. The stack is then placed inside a special plastic bag. 

 

When an item is placed in the vacuum sealer, all the air is sucked out of the bag and it is sealed closed. During this process the moisture from the pages is drawn into the dry blotter between the pages. The pages, which were relaxed by the moisture, are drawn flat by the pressure. We generally leave a book in the sealed bag overnight. Ideally, we open it the next day and the book is perfectly flat.

Monday, July 13, 2009

Many of the files from the African American Museum contain various forms of correspondence. There are many postcards and letters with their original stamps. When these already fragile envelopes were faced with the flood, the stamps detached to end in a pile at the bottom of the file folder.

The second project I gave Kallie was to reunite the stamps with their respective letters and postcards. This was a fun project because it’s like putting together a puzzle and some of the stamps are pretty interesting. I had her reattach the stamps using wheat starch paste applied with a small brush. When the stamp was in position, a small square of blotter was placed over it and weighted to absorb any excess moisture and prevent warping.

Friday, July 10, 2009

We have a new  volunteer! Kallie Holt, a Junior at the University of Iowa has volunteered to work 8 hours a week here in the Conservation Lab.

The first project I gave her was the cleaning of a collection of small miscellaneous items from the African American Museum. These objects range from pacemakers to a wooden gavel and everything in between. Most of the collection belonged to a medical doctor, hence the medical paraphernalia and miniature lungs which you can see at the bottom of the photo on the right.  Creepy.

Tuesday, July 7, 2009

We have encountered every problem in the book (no pun intended) while treating these ledgers for the Johnson County Historical Society. These two pictures of the same ledger are good examples. The structure of the book was sound. It needed a little bit of cosmetic repair and hinge repair. The inside is a different story. Almost all the pages are illegible, the ink has run and bled obscuring most of the text in the ledger.

In the front of the ledger was taped a small pamphlet. It was in relatively good shape. When it
got wet in the flood some of the dye from the orange paper transferred to the pages around it. I dry cleaned it, removed the staples and took off the tape with a heat spatula and vinyl eraser.

The tape left in the ledger I did not remove because it would have made a mess of the paper trying to scrape and melt it off. While it is not ideal to have tape in the book, as it gets older the tape will become brittle and flake away doing far less damage.

Monday, July 6, 2009

There are several different types of ledgers from the Johnson County Historical Society. This ledger was completely detached from the covers, but the case was intact. The spine and corner pieces were in good shape but the cover cloth was warped and bunched.

I began with the text block. I tipped in some pages that had become detached and then put the ledger in the job backer to re-form the round of the spine. It’s not hard to do with these books since they are so used to being rounded they just need a little coaxing. When I got the spine into the position I wanted it I used wheat paste to line the spine with a piece of kozo, a thin japanese paper which I stippled on with a stiff brush. While that dried I used a piece of kozo and wheat paste to reinforce the spine inside the cover, carrying it across onto the boards to give the hinge area more strength. I added new black cloth to the covers to “pretty them up” and set it under weight to dry. When the spine of the text block was dry, I added a cambric (cloth) lining with flanges overhanging each side of the spine about an inch. When that was dry I put the text block back into the original cover using pva to put down the cambric onto the japanese paper lining inside the cover. I then pasted the original paste-downs to the cover using wheat paste. When the whole thing was put together I placed it in between press boards and put it in the job backer so it would dry in the right shape.

Wednesday, July 1, 2009

This ledger from the Johnson County Historical Society was in bad shape. The boards were warped, the spine piece had come detached, and the covers were almost completely off but for one small area. The covers were so far gone I decided to replace them altogether. I kept the cloth from the front board so I could attach the title to the front of the new case.

The board that most of the covers are made of was excellent at sopping up all kinds of flood goo and smells absolutely horrible. When we
can, we keep the original covers but in a situation like this it made more sense to completely rebind the ledger. Since we didn’t need to keep the cover boards I was able to peel the layers away from the areas of the page that didn’t release easily, without risk of tearing the paste-downs.

Tuesday, June 30, 2009

While processing manuscript archive documents from the African American Museum of Iowa we fortuned upon an old, mysterious and extremely problematic form of document duplication.

What we believe we have, perhaps hundreds of, are adherography documents.  A definition, found in “Guide to the identification of prints and photographs : featuring a chronological history of reproduction technologies” – a supplement to the book “Encyclopedia of printing, photographic and photomechanical processes,” by Luis Nadeau, 2002 – is as follows:

ADHEROGRAPHY: A duplicating process developed by 3M. Images were formed by the adherence of powder to a tacky latent image created by the effect of infrared heat. This provided a master from which 200 to 250 copies could be made. The powder image of the resulting print was fused to the paper by heat. [A process used during the 1960’s.]

These adherographs, recognized as inherently volatile, did not respond well to the moisture, humidity, and high temperatures generated by last June’s floods.  The powder image described above, once fused to a slick-feeling, glossy-looking paper carrier, have lost their bind to their paper hosts.

Reformatting is simple where the powder images free themselves in large pieces.  Unfortunately, many of the documents have experienced a shattering of the powder image layer.  Attempts to stabilize these particular documents in sonically-welded Mylar encapsulations have both pros and cons.  On one hand, the Mylar, having a strong static charge, lock the powder image fragments into place… useful for reformatting.  On the other hand, this same static charge has the tendency to agitate the fragments into incomprehensible disorder.

With the jury still out on encapsulation, we simply reformat through the best possible means.  Where the documents are relatively stable, we quickly scan them face down on the Ricoh.  Where the documents are highly volatile, we image them under the Zeutschel top-down scanner.  No digital files are maintained.  Determining the best solution for the shattered documents requires further research.  Stay tuned.

Friday, June 26, 2009

As conservation work moves along for flood-affected artifacts from the African American Museum of Iowa, we momentarily shifted away from treatment of metals to pick up our inventory of small objects comprised of a variety of media. Two primary functions of the inventory are to verify the holdings under our care against the original AAMI data and also to provide our own identification number for the artifacts. Tagging the artifacts with both IDs and generating descriptive data for our flood recovery inventory helps us track and evaluate where we are in the treatment process, and, consequently, how much work we have left to do.