Replacing Collection Objects

Back to complete list of Exhibit Technical Notes

The replacement of fragile, sensitive, or highly valuable collection objects with non-accessioned replicas, reproductions or period objects is sometimes necessary for the protection of museum collection objects.

How can replacement objects be used as a preservation tool?

Replicas, reproductions and copies of original objects are used in some exhibit situations when an institution’s collection does not contain a specific, required object. The use of such non-collection materials under conditions that may damage a collection artifact can also be a powerful tool of the institution’s preservation policy. Situations that may require a non-collection item to be used because of conservation concerns include:

• the physical circumstances of the exhibit are inappropriate for display of collection objects;
• a collection object is inherently too vulnerable (or rare) to be put on display;
• the condition of an object is too unstable to go on display;
• a collection object must be rotated off display and no similar replacement object from the collection exists;
• the object will be used as part of a demonstration or hands-on program.

What are the guidelines to follow when selecting non-collection objects?

A principal guideline for selecting non-collection items is choosing reproductions made from stable materials. Reproductions should not emit harmful substances, or contain dyes or pigments which could be transferred to nearby artifacts. This is especially important if the reproduction touches a collection object, or is located in a case or other confined space with collection objects.
Replicas or reproductions are sometimes created using the same materials and techniques as the original piece; they may even be produced by the same manufacturers. To avoid future confusion, permanently mark a reproduction or replica with the current date (i.e. 1999). Labels that clearly identify an object as a replica or reproduction allow the informed public to evaluate that object as a non-collection piece.
Artificial aging or distressing can make new items look aged. Curatorial intent determines whether or not these techniques are appropriate. In general, artificially aged objects should always be identified to the viewing public. Label copy can include the "preservation reason" behind using a reproduction; for example:

"This reproduction object has been used because the original (seen in the photograph) is too fragile to be placed on long-term exhibit."

Are there risks involved when making reproductions of a collection object?

Many museums buy reproductions available on the commercial market, or use unassociated, period objects that have little collection value because they lack documentation or are very common. Another category of non-collection objects used in an exhibit setting are copies created specifically for the exhibition.
Creating copies of a collection object exposes that object to a great deal of risk; objects have been damaged, for example, during the mold-making process and by rough handling. The methods and materials used to produce the replica must be safe for the collection object. In addition, the person undertaking the reproduction process must be sensitive to handling museum objects and must be willing to take direction from museum staff.
The procedures for replication should include the following polices:

• Have a conservator examine the artifact before any replication processes occur to insure that the artifact can withstand handling. If the object is fragile or is susceptible to damage from the reproduction process that will be used, select another object for reproduction or use a commercially available reproduction.
• Have a conservator review all methods and materials used in the reproduction.
• Set limitations for the handling of the artifact; only qualified museum personnel or a trained crafts person should handle the artifact, and the object should be handled as little as possible.
• Include the unacceptability of object damage in the reproduction contract.
• Restrict the object from leaving the museum premises.

Are there any special precautions for making two-dimensional reproductions?

Using a color copier is the least expensive method for reproducing two-dimensional objects. Trained museum staff should handle the artifact. Limit the number of times that the original is exposed to the light of the copy machine. The object must fit onto the glass imaging plate of the machine without being folded, bent, creased or otherwise damaged. When copying books, use special machines that support the binding.
Good photographic reproductions can be made from a 4x5 transparency of the document. Having such a large transparency made usually requires taking the object to a professional photographer. Ifachrome (also called Cibachrome) is the most chemically stable process for color images. The process prints onto a polyester base instead of paper, but costs about the same as paper development. Photographs can also be printed on papers that imitate the original material.

What conservation issues are involved in making three-dimensional reproductions?

Several methods are available to reproduce a three-dimensional object. Casting a replica from a mold taken from the original is perhaps the most common technique, especially for intricate objects or when multiple copies are to be made. Individually crafted reproductions based on exact measurements is another frequent technique. For some uses, the artifact is copied using original materials and techniques. When exact reproduction is less important, other materials that may be easier or cheaper to work with may be used, as long as the material is stable.

A few issues to consider are:

• Casting a replica from a mold taken of the original is a multi-step process that can be detrimental to the original artifact. In order to prevent damage, employ a professional cast- maker or museum specialist and insist that they follow guidelines outlined by a conservator. It is especially important that the mold material does not shrink around the object, and that an appropriate isolating layer be used to insure that the original is not contaminated.
• Faux finishes, wood laminates and photographic inserts are inexpensive methods of reproducing many finishes. These finishes imitate the original from visitor viewing distance, but are easily identified upon close inspection. These finishes may require special cleaning techniques.
• The use of undocumented or duplicate artifacts from the same time period is an alternative to a reproduction. Often identical to the original, such artifacts require careful documentation to prevent confusion. It is advisable to permanently mark these objects as exhibition materials or hands-on objects.

Products, Manufacturers and Suppliers

Mention of a product, manufacturer, or supplier by name in this publication is for information only and does not constitute an endorsement of that product or supplier by the National Park Service. Listed materials have been used successfully in past applications. It is suggested that readers also seek alternate product and vendor information to assess the full range of available supplies and equipment.

Replica Manufacturers

Replica Resource List (computerized database)

The Association for Living Historical

Farms and Agricultural Museums

The Photographic & Reprographic Group, Inc.