CONSERVATION & TREATMENT
Conservation/Treatment of a collection should be completed prior to submission of the collection for long-term curation.
For information on the treatment of archaeological materials prior to long-term storage, consult the bibliography listed in Appendix 1. These publications discuss care in packing and storing a variety of materials including metals, ceramics, stone and brick, glass, bone, leather, wood, and textiles. Basic techniques are described to safeguard and protect artifacts from the time they are unearthed until they can be treated in a laboratory by a conservator. It should be kept in mind that constant experimentation in conservation methods periodically leads to abandoning techniques and materials previously recommended.
Additional points to remember when considering treatment of collections are that often the best course of action is no treatment and that any treatment should be reversible. The collections managers of the repositories should be consulted prior to treating materials. If needed, a professional conservator can be contacted through the Survey.
Normally pieces of an object should not be joined. If joining is performed, procedures for treatment must be followed and only reversible adhesives should be used. White glues such as Elmer's are not acceptable. White glues cross bind with molecules of the object making it impossible to remove without also removing part of the object. Other unacceptable glues are hide glue, rubber cement, silicon glues, epoxies, and instant-bonding glues. Uneven joins put an object at high risk when handled and make it unsafe for exhibit or loan.
If an object has been treated or joined, it must be accompanied by a report describing the procedures and chemicals used for the purpose of the treatment, date of treatment, and name of the person who performed the treatment. Precautions to follow in future handling of the item should also be noted. The repositories will not accept treated objects without this documentation.
Packaging is part of the conservation process and consultation with a conservator is encouraged, particularly with regard to perishables such as bone, skin, or hide products, wood, textiles, or basketry.
Use common sense in packaging materials to avoid abrasion, breakage, and general deterioration of condition. The use of polyethylene zip-lock type bags, non-buffered acid-free tissue paper, and boxing of fragile items, using acid-free boxes and inert support materials such as ethafoam help to serve these purposes. Materials requiring special handling or care, such as feathers and textiles, should be separated from the remainder of the collection and labeled clearly with their special needs.
The size of exterior packaging boxes must match the requirements at the various repositories. Refer to the specific requirements of the individual repositories for guidance on the type and size of storage boxes. When factors such as item weight or dimensions preclude the use of the standard size boxes, alternative packaging will be accepted. The repository should be notified of any exceptions prior to arrival of the collection in order to make necessary storage arrangements.
Interior packaging should be appropriate to the materials stored and their individual conservation needs. Always separate objects by material type (e.g. bone and stone should not be packaged together). Diagnostic and fragile objects should be packaged separately from bulk lots.
Most objects can be packaged in zip-lock polyethylene bags that have been perforated (e.g. with a paper punch), but for long term curation it may be necessary to repackage organic items. Feathers should not be placed in these, as static electricity can be strong enough to pull off barbs and barbules. They should be packaged flat in a rigid, acid-free container which is well padded with non-buffered acid-free tissue.
Each interior box or bag should be labeled with the site number, collector's (or project) name, year of collection, and the catalogue numbers of the enclosed items. It is recommended that labels on plastic bags be supplemented with acid-free paper labels inserted in the containers so that they can be read without opening the bag. If material from more than one site is packaged in the same box, materials from the different sites must be segregated using box dividers with the interior bags or boxes clearly labeled with the required information.
Analytical samples must also be packaged and labeled. Bulk soil, floral, and faunal samples may be placed in polyethylene zip-lock bags. Double bagging is preferred. Radiocarbon samples should be packaged in the same manner used for submission to dating laboratories. Care must be taken to insure that all samples are dry prior to being bagged for storage. Failure to do so may destroy their value for future analysis. All sample containers must be labeled with the site number, type of sample, catalogue number, date the sample was taken, the name of whom took the sample, and the sample's provenience (if the latter information is not recorded in the catalogue.
The following information must be printed on the end and at least one side of each exterior box:
- Site Number(s)
- Site Name (if there is one)
- Project Name
- Collector's Name (if there is no project name)
- Year of Collection
- General Description of Contents
- Provenience of Contents
Maps, drawings, etc. should be placed flat and unfolded in oversized folios or carefully rolled in map tubes. If oversized documents are rolled, use fabric bands or strings to secure them, as tape and staples add to the deterioration of such documents. The folio or map tube must be labeled on the exterior with the site number, project name, and subject(s) depicted on the enclosed drawings or maps.
Each container of material submitted for long-term curation must be accompanied by a complete inventory listing of its contents. This inventory list will serve as a basis for verifying receipt of all materials, for computer entries for the material retrieval system, and for establishing responsibility for missing artifacts in future inspections.