Guidance for Archaeological Archiving#

4. CARE AND CURATION OF THE ARCHIVE #

Although this section appears after those on planning, data gathering and analysis and report writing, it should be made clear that care of the archive components should actually begin to take place as soon as any data is created or material collected and continue on throughout the project; it is not something which should only take place once the archive has been deposited at the end.

The project team should ensure that all elements of the archive are maintained to the best standards possible throughout the lifecycle of the project. (See STANDARD for archaeological archiving Chapter 3).

Therefore this section should be read as applying to every stage of a project up to and including permanent storage of the archive. As such it has been necessary to target the advice to different situations identified for the purpose of this guidance as:

Active use: applies to when the project team members including conservator-restorers and specialists are actively working on project data and archaeological materials.

No longer in active use: applies to when some or all parts of the project have been completed and the use of some or all items from the documentary and/or material archive is finished, but the project archive has not been deposited into a repository for long term curation.

Temporary storage: applies to the storage of documentary and material archive components after the archive has been compiled for transfer, and project work is thus completed, but before it has been deposited with a repository for long term curation.

Long term curation: applies to the long term care and management of an archaeological collection in a repository.

4.1. Care of documentary and material archive components in active use#

  • During data gathering, analysis and report writing, archive components in active use must be maintained in the best conditions possible, and every effort must be made to ensure that the risks of damage, deterioration, fading, damp, theft and loss are minimised.
  • Whilst in general use by project teams and specialists, all documentary and material archive should be handled with due care and attention. Wherever possible both material and documentary archives should be protected in the appropriate storage boxes, sleeves or cabinets. Digital data should be subject to internationally, nationally, regionally or locally recognised information technology management procedures.
  • Appropriate storage conditions for all elements of the documentary and material (finds) archive must be maintained throughout the phase of active use. It is important, for instance, to recognise that conserved and un-conserved objects may require different environments.

4.2. Care of documentary and material archive components no longer in active use#

Once digital data are no longer in active use a system of regular back ups along with good data management housekeeping may be no longer enough to protect the data, especially in cases where transfer to a digital repository can take a number of years. Technological change can be rapid and the physical media on which data are stored are not permanent. What went into storage may quickly become obsolete and unreadable. Therefore this Guide recommends the preservation of digital data by migration: i.e. continually migrating information from older hardware and software to newer systems. Some archaeological practices may not have the resources to act as a de facto digital preservation repository, however there are a few simple steps which can be taken to ensure the maintenance of the digital archive once the data is finalised and out of active use:

  • Once documents and images created on analogue media are complete they should be moved as soon as possible from active office use into archive storage until eventual deposition.
  • The guidance provided in sections 4.3 – 4.5 should be followed as far as is practically possible for all documentary and material archive in temporary storage prior to deposition.
  • Once work on individual digital files has ceased they should be moved to the project archive and that should be recorded.
  • Digital files should be fully indexed within the project archive and certified as virus free before storage.
  • Once in the project archive all digital files should be actively managed as set out in 4.4 below, in order to prevent obsolescence.

4.3. Accommodation for archives in temporary storage#

It is highly desirable that the temporary storage time prior to final deposition is kept as short as possible. However it has to be accepted that in some cases, especially where projects are large or long running, temporary accommodation of the archive can last many years whilst analysis and report writing are undertaken. Wherever possible, temporary storage conditions should adhere to the national, regional or local rules for permanent storage of archaeological collections.

  • Ensure that any stores housing the documentary or material archive are not at risk of destruction or damage by vibration, contamination or breakage through natural or man-made causes such as fire, floods or tidal waves, earthquakes or landslides, explosions or pollution, either on-site or in the vicinity. Avoid and protect against rodents, insects and other pests.
  • Ensure that supply systems for electricity, gas, and especially for water are kept well away from storage areas, and that the building has a fire detection system.
  • Minimise the amount of movement of stored objects and store archive materials in the dark.
  • Ensure that stores are kept at the temperature and relative humidity appropriate for the objects according to national, regional or local recommendations. It is generally accepted that there is an increasing risk of microbiological activity above 60% relative humidity, and increased brittleness at a very low relative humidity. However across Europe with its variety of climatic zones, different limits have been recommended and there is no general agreement, either upon temperature or humidity, but it is established that most archive categories last longer at lower temperatures and at lower relative humidity. Reference should be made to national, regional or local standards and bibliographical information for these can be found on the BIBLIOGRAPHY part of the ARCHES website.

4.4. Long term curation of the documentary archive#

See STANDARD for archaeological archiving Chapter 2.

  • Digital data
    • All files should be provided with data documentation. Data documentation enables clear access to the data and helps prevent loss of information during the process of data refreshment and migration, as the character of the data is well understood. All files should be provided with sufficient metadata to ensure that the data in the file can be easily accessed and understood. This will enable digital data to be useful to someone other than its creator in years to come.
    • Data refreshment should be practised. Digital data should be checked for readability on a regular basis, and where necessary data should be copied from one magnetic or optical medium to another as the original nears the end of its useful life.
    • Data migration should be undertaken according to current best practice principles in data and information management, which can change rapidly. To make files independent of the machines and the software they were made with, files for archiving should wherever possible be transferred from proprietary formats onto stable and persistent preservation formats, and migrated onto successive versions of these formats as software updates or changes (Examples are .xml for text and spreadsheets, .jpg and .tiff for images, and .dxf and .svg for vector drawings. Proprietary formats such as .doc, .pix, and .ai should be avoided. Sometimes a proprietary format is allowed because it is widely accepted –de facto- standard such as the .pdf format (PDF/A (ISO 19005)). All files and metadata should be validated during this process and earlier versions should not be discarded until the newer one has been checked.

It is not possible to discuss in detail the standards for digital archiving in this Guide. Detailed guidance on digital archiving can be found in the OAIS reference model (OAIS - Open Archival Information System (ISO 14721)), the Guide to Good Practice section of the Archaeology Data Service website (http://Guides.archaeologydataservice.ac.uk/), the Digital Archiving and Networking Services (DANS), and websites that follow or instigate developments and discuss these, such as JISC (http://www.jisc.ac.uk/about)and the Forum on Information Standards in Heritage (FISH)(http://www.fish-forum.info/). For more information on how data can be linked and openly accessed and re-used the site of Linked Open Data is a good starting point (http://linkeddata.org/home). A practical guide on how to organise research data is given by the UK Data Archive (Van den Eynden, V. et al 2011. “Managing and sharing data; best practices for researchers” University of Essex, Colchester, Essex http://www.data-archive.ac.uk/media/2894/managingsharing.pdf).

  • Analogue documentation
    • Analogue images and documents may take different forms with specific archiving requirements. Several general points may be articulated:
    • All paper should be stored flat in acid free, dustproof cardboard boxes.
    • Drawings on drafting film should be stored flat in dust free containers.
    • All paperwork should be fully indexed and separate classes of documents should be grouped together. An overall archive index and a title sheet marking different groups of documents should be present.
    • Documents of the same type should be organised in a logical order, by context, date and object number as appropriate.
    • Any binding or labelling which could damage analogue information, such as elastic bands, staples, paperclips or self adhesive labels or tapes should be removed.
    • Boxes should be stored in a dust free, dry and preferably dark environment, and well away from environmental hazards such as damp, insects or rodents.
  • Photographic (analogue) material
    • Generally, photographs should be treated as specified in the section above. However since photographic images are very vulnerable to deterioration in poor storage conditions, several particular points apply:
    • Prints, negatives and transparencies, including x-radiographs should be stored in acid free paper enclosures or polyester sleeves in archival boxes or dust proof cabinets.
    • All films and photographs should be fully indexed and labelled with the project identifier and other appropriate information such as the film or frame number, in a manner which does not damage the image or have the potential to rub off during handling.
    • Photographic material is especially sensitive to light damage, which causes fading, and it keeps better in a cold environment. Photographic material should be stored in boxes or cabinets in a dark, cool, dust free environment and well away from any potential environmental hazards.

4.5. Long term curation of the material archive #

See STANDARD for archaeological archiving Chapter 2.

  • General Guidelines for all classes of material
    • Where appropriate, material objects (finds) should have been cleaned before transfer to long term storage.
    • Any conservation work, including the cleaning of sensitive objects (finds), should be undertaken by a qualified conservator-restorer, be carried out prior to long term storage, be fully documented and the documentation added to the project archive.
    • The material archive should be stored according to type, sensitivity, packing and storage requirements and different classes of material should be kept separate.
    • The material archive should be fully indexed and cross referenced to its record, which should accompany the material archive into long term storage and be stored with the digital/photographic/paper archive as appropriate.
    • The material archive should be labelled or marked with all object, site and context information as appropriate, and with identifiers that are legible, visible, permanent and not easily separated from the object.
    • Boxes should not be overfilled and should contain adequate cushioning such as inert foam or acid free tissue between any fragile objects.
    • Boxes should be stored in darkness, off the floor, in an environment appropriate for their contents, which minimises the risks of damage or deterioration.
    • The storage environment should be monitored regularly and protected against large fluctuations of temperature and humidity. Checks or monitoring traps should be set to warn of any rodent or insect infestation.
  • Special types of finds
    • Before accepting the material (finds) archive for long term storage, ensure that any objects that were recovered wet or damp have been dried out and received the appropriate conservation treatment.
    • Metal objects should be packed in accordance with current conservation guidelines and specialist advice. Any humidity strips or silica gel must be monitored on a regular basis and regenerated, dried or changed as necessary.
    • Ensure that all x-radiography has been carried out as appropriate and the associated images and records are fully cross referenced to the objects.
  • Material recovered from scientific sampling
    • Generally, scientific samples should be treated as specified in the general Guidelines above. However several particular points apply:
    • Some samples may be subject to destructive analysis, so that nothing or little is left of the sample. This should have been recorded in the archive and the data from analysis stored with the documentary archive.
    • Sample analysis, (such as thin sectioning, soil or pollen analysis) may result in the preparation of microscope slides. If the originals are to be kept in the laboratory as reference material, then the documentation should be in the archive in long term storage and where possible a duplicate set of slides should accompany these records.
    • Column samples can be stored in cool dark conditions. Analysis should be carried out as promptly as possible and the data preserved in the archive.
    • Wet or damp samples, such as waterlogged wood and flotation samples, must not dry out and should be kept cool, refrigerated if advised, in watertight containers. The condition of the samples should be monitored on a regular basis.
  • Human Remains
    • Human remains may be subject to special licences or permissions, including the requirement for reburial or restrictions in time allocated to the analysis period. When human remains enter storage, conditions relevant to their curation should be highlighted in the archive documentation and those conditions should be monitored and followed during storage.
    • Wherever possible human bone should be packed and boxed in such a way that individual skeletons can be distinguished.
    • The treatment and curation of soft tissue remains should be subject to specialist advice.