Northern States Conservation Center

Providing collection care, preservation and conservation treatment services to collectors and collecting institutions.

Collections Caretaker

Collections Caretaker (July 29, 2010)
July 29, 2010
Northern States Conservation CenterNorthern States Conservation Center
The Collections Caretaker e-Newsletter
In This Issue
Preventive Conservation of Paintings
To Preserve Our Collections We Must Understand How They Were Constructed
The Monster in Our Museums: Old Loans and Abandoned Property
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MS 001: The Problem with Plastics
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Welcome to the Collections Caretaker e-Newsletter from Northern States Conservation Center. Our old Collections Caretaker is now in a new electronic format to bring you timely and helpful content that is pertinent to situations we all encounter in our museum and archives work. Feel free to let us know what topics you would like to see featured in Collections Caretaker or even contribute an article.
Preventive Conservation of Paintings
by Victoria Montana Ryan

What is meant by preventive treatment? Conservator Maggie Graham-Bell says preventive conservation is doing what we can to prevent ongoing deterioration by problems of materials, methods, environment, and people - in other words stabilization. Sometimes simple, common sense steps can provide a great benefit for the long-term stability of an artwork. While proper handling and good environment are key steps in preventive conservation there are other things we can do.

For paintings, the most basic preventive care step is the addition of a good backing board. If all artists and galleries used backing boards, I would have a lot less work.

As conservators, we are always trying to improve the status quo. A cardboard backing is better than none, an acid-free cardboard backing is better than one of acidic cardboard, and a Fome-Cor or Coroplast (corrugated plastic) backing may be better than one of acid-free cardboard. Backing boards provide protection against physical contact, dampen vibration when moving, reduce dirt and debris on the canvas, and buffer environmental changes to the back of the canvas.

Another aspect of preventive conservation is knowing when it's time to call the conservator. If you notice a new damage or problem or see something you think may cause damage, don't hesitate to contact the conservator. Don't be tempted to try removing even minor blemishes such as small stains, blobs, spit wads, or graffiti. This may lead to further damage. Call the conservator.

(excerpt from the course MS227: Care of Paintings)

Vistoria Montana Ryan teaches the online class MS227:Care of Paintings. She is a former Assistant Professor for the Conservation of Paintings at Queen's University Kingston, Ontario and former adjunct faculty member at the University of Denver where she was conservator of paintings at the Rocky Mountain Conservation Center for over a decade. Victoria Montana Ryan received her Master of Art Conservation from Queen's University and a Master of Arts degree with an emphasis in Art Education/Museum Studies from the University of New Mexico. Ms. Ryan has authored papers on the care of paintings, integrated pest management, and the importance of working with appraisers; she has also appeared on the Discovery Channel to discuss care of personal treasures.

To Preserve Our Collections We Must Understand How They Were Constructed
by Helen Alten

In the beginning, there was the earth. And from the earth grew plants and animals. And the earth was made of stone and rocks. And from this bounty, man experimented, invented, devised, decorated and created shelter, body coverings, cooking implements, transportation vehicles, toys, computers and, perhaps the most significant inventions of the 20th Century, Spandex and Velcro. Together this comprises everything that would eventually end up in museums as representations of "material culture." And we, the caretakers of the material culture of our ancestors, find the variety and creativity staggering. Especially as we fight our biggest demon - aging. To preserve our collections, we must understand how they were constructed and how the material reacts with our environment to deteriorate, or how the manufacturing process may include its eventual deconstruction.

To understand the materials found in our museums, we start by understanding the materials from which they are constructed. This means, we need a cursory understanding of plant biology, animal physiology and geology.  A touch of physics and chemistry help explain how raw materials are processed into the finished artifacts that make our material culture. As caretakers, you are not meant to be experts in any of these subjects. But you do need to understand the construction process in order to understand what might detrimentally affect the artifact. 

A Silver Bracelet

Let's use a silver bracelet as an example.  The silver was extracted from an ore - a rock - and melted, cold worked or heated to form the bracelet. There might be tool marks on it that need to be preserved.  From chemistry, we know that silver is less stable than silver sulfide. The tarnishing and corrosion of silver occurs rapidly if sulfur is in the environment.  This starts as an iridescent shimmer on the surface and eventually turns the bracelet completely black. Where does the sulfur come from?  Again, knowing materials and their chemical make-up helps us determine possible sources.  Wool and hair produce sulfur as they deteriorate.  Fire-proofing is a sulfur compound that might be added to textiles or other materials.  Rubber has sulfur added to it to harden the latex.  This tells us that the storage environment should be free of any material that has sulfur in it.  Separate silver from wool textiles and rubber balls, for example.  Storage might also be improved by using sulfur scavengers, reducing the amount of sulfur reaching the silver bracelet.  Sulfur scavengers include silver cloth (a polyester felt impregnated with fine particles of silver), which we recommend be wrapped completely around stored silver.

Now, should we clean it with an abrasive polish?  Or should we use a silver dip?  How often should we clean it? All of these are answered if we understand the chemistry and physics of removing the silver corrosion products.  Silver corrodes between the metal grains.  Polishing with an abrasive wears off the top layer that is corroded, revealing shiny silver.  But some corrosion remains between each silver grain.  For this reason, old silver looks a little darker and more pewter colored than new silver.  A silver dip attacks and removes ALL the corrosion.  Even the intergranular corrosion, leaving voids between the grains.  This makes the silver more brittle and less flexible. It results in a bracelet that is more likely to snap or crack.

The answer to how often silver should be cleaned is - no more than once, if you are storing and handling it properly.  By eliminating the sulfur in the environment, and not touching a cleaned surface, cleaning should be a rare event. Especially since cleaning is abrasive - wearing down the surface each time it occurs.

Thus, knowledge of chemistry, physics and materials science helps us determine the best way to care and clean a silver bracelet.  

(excerpt from the course introduction to MS 213: Museum Artifacts: How they were made and how they deteriorate)

Helen Alten is the Director and Chief Objects Conservator of Northern States Conservation Center and the instructor for the online course MS 213: Museum Artifacts: How they were made and how they deteriorate. She has spent 25 years working with small and large museum on preservation and conservation issues.

The Monster in Our Museums: Old Loans and Abandoned Property
By Lin Nelson-Mayson

Information anxiety is the black hole between data and knowledge, and it happens when information doesn't tell us what we want or need to know.

They may lurk on the back shelf of your storeroom. Perhaps they rest in that case down the dark hall where no one ventures. Forget Hollywood's monsters: these are true museum mysteries - old loans and abandoned property. Nearly all collecting museums confront the problem of old loans and/or abandoned property. However, we don't need to hide the problem. Bring these stray items into the sunlight and face them with a plan.

Unfortunately, museums have a bad habit of accepting loans with limited documentation, "permanent" loans and objects with little or no documentation - and a lack of institutional memory about them. Many states have laws that define these situations and remedies for them. Museum organizations, in turn, have developed workshops that explain how to meet these legal requirements and to establish ownership of unclaimed loans and undocumented objects.

So why should you be concerned? Although these items may not seem like pressing issues, their very age and the uncertainty surrounding them make addressing the problem important. The passage of time makes these mysteries harder to solve. Without legal title to an object, a museum bears full responsibility for storage, insurance, record keeping, security and climate control, but is unable to take appropriate actions with an object. 

Holding old loans takes up many museum resources, including staff time, expensive-to-maintain storage space, and annual insurance coverage. A loan or unknown origin item must be treated with the same care as an accessioned item. Some argue that loans should have the best care - since they are NOT owned by the institution and could be a liability if damaged through mistreatment. This means climate controlled storage spaces, storage mounts, and careful handling practices.

Searching for owners is a burdensome process. Often it involves researching genealogical records, writing to county courthouses for address and probate records, writing to cemeteries, searching old telephone books, and sending letters to possible descendants.

In the 1980s, museums brought the problem to various state legislatures. They encouraged laws to help museums and archives legally pursue title to old loans and abandoned property. These laws are designed to create procedures for establishing ownership. They typically address each type of problem object. And they establish processes for determining status within the museum, procedures for publicly seeking original owners, and processes that allow museums to assert ownership if no one comes forward to claim an object.

The value of these laws is stated in the "Proposed Minnesota Museum Property Act:"

Without such legislation, museums hesitate to deal with the unclaimed and undocumented items because of potential liabilities should the original owner appear and prove ownership. Abandoned property legislation, as this type of law is commonly called, establishes the mechanism by which a museum can terminate a loan and take title to unclaimed property. A museum can then use the property for any purpose related to its mission, or if unrelated to its institutional mission, the museum can transfer the property to another repository or dispose of it. It is important to note that this law is not regulatory in nature, but rather a tool created for a museum's voluntary use. It does not require museums to convert privately owned material to museum property, but if a museum has a need to do so, the law would place the legal means at its disposal.

From the perspective of the profession, the practice of accepting "indefinite" and "permanent" loans is heavily discouraged. Cataloging procedures are generally more thorough today than in the past. Museums are responsible for establishing and maintaining protocols that protect them, as much as possible, against problems that may arise from a lack of documentation or lack of contact with lenders.

(excerpt from the course introduction to MS 303: Found in the Collection: Orphans, Old Loans and Abandoned Property )

Lin Nelson-Mayson, with over 25 years of museum experience at small and large institutions, is director of the University of Minnesota's Goldstein Museum of Design. Prior to that, she was the director of ExhibitsUSA, a nonprofit exhibition touring organization. Ms Nelson-Mayson's experience includes teaching museum studies and museology courses. Her particular interest is the needs of small museums.
Northern States Conservation Center (NSCC) provides training, collection care, preservation and conservation treatment services. NSCC offers online museum studies classes at in Collections Management & Care, Museum Administration & Management, Exhibit Practices and Museum Facilities Management.
Helen Alten, Director
Brad Bredehoft, Sales and Technology Manager

P.O. Box 8081, St. Paul, MN 55108   Phone: (651) 659-9420

© 2002 Northern States Conservation Center

Updated 11 May 2002