Lately there has been a long thread on the Archives-NRA discussion list on the best kinds of paperclips to use on archive collections, and although I sympathise with the undoubted incredulity of the rest of the world that anyone could care two pins (or brass clips) about this kind of thing, I remembered that I wrote this in my first year of work as a qualified archivist, at Glasgow University Archives.
Brass, stainless steel or plastic paper clips?
A survey of advice on fasteners for paper collections
A survey of advice from a variety of sources including Conservation Online, including their discussion list for conservation professionals and recommended external links, the National Preservation Office and the National Archives revealed the following:
The National Preservation Office says in its Basic Handling Practice leaflet that ‘Pressure tapes, metal or plastic fasteners such as paper clips and pins should never be used, and must be removed by trained staff.’ The use of any paper clips at all is a compromise; the best way of keeping a small set of papers together is to put them in an acid-free paper folder or enclosure, but if there are many of these sets, the extra paper takes up a lot more space. Another point against using fasteners of any kind is the difficulty of getting readers to use them properly: systematically removing them one by one to examine individual papers (rather than folding them back on each other, bending and folding papers and risking tears and further damage) and similarly putting them back!
Several sources recommend as a safer alternative, although not ideal, stainless steel paper clips with a slip of acid-free paper between the clip and the documents. This prevents direct damage e.g. rust from the metal clip but would be fiddly to implement and difficult to enforce with users. The increased use of acid-free paper would partially offset the overall lower cost of stainless steel paper clips. This option tends to be recommended by sources in the U.S.A., who seem to use mostly stainless steel or aluminium paper clips rather than either plastic or brass.
Archival fabric tape is also an unacceptable way of keeping bundles of papers together as it causes immediate stress and tearing on the outer edges of the documents, the tape tends to be used to remove bundles from the box, users are often not careful enough about how they undo it, and further damage may be caused by retying the tape too tightly. Papers in a bundle are often not exactly the same size, which exacerbates the problem. Bundles of papers, leaflets etc. too big for a paper clip should be kept together by a paper or card folder or enclosure, as should any particularly fragile papers. The folder can then be secured with fabric tape if necessary. I should perhaps mention that all the sources I consulted were unanimous and emphatic in stating that the use of any pressure-sensitive tape, including ‘archival’ or ‘conservation’ repair tape, for mending tears in paper, is not advisable.
Metal pins rust, make holes in paper, cause wrinkles and are a safety hazard. They must be removed – this is often difficult in cases where rust is holding a number of sheets together. Treasury tags, often used to hold larger numbers of papers together in one corner, are also unacceptable – they require making a hole in each sheet and do not hold the sheets in a stack, so that it is easy for them to fall and tear during handling.
Plastic clips, and Plastiklips are mentioned specifically, are cited by Conservation Online discussions as causing more bending and crimping of paper than metal paper clips. These indentations will eventually lead to tears. They may also offgas in the event of a fire; a more ordinary risk is that they will break, either actually tearing the paper or allowing it to slosh about in the box or fall on the floor when accessed. Plastic tends to degrade over time and will become brittle. Also, plastic clips cannot be bent to adjust to slightly thicker groups of papers and will simply exert more pressure, increasing both damage to the papers and the likelihood of the clips breaking. Plastiklips expand a bit but this expansion exposes the papers to another set of edges, causing more crimping. They are no less likely to cause tearing when attached or removed than properly made metal clips. Plastiklips are significantly thicker than most metal paper clips and even when the placement of clips along the top edge (the safest place as it will be noticed immediately) is staggered, cause uneven stacking of papers in boxes or folders, leading to possible damage and wasted space.
Brass paper clips
The HMC’s Standing Conference on Archives and Museums specifically recommends the use of brass paperclips, and the Conservation Online discussion group cites their use as standard European practice. They are inert and will not rust, break or become brittle. Use of any paper clip is a compromise, but where it is necessary or practically expedient solid brass paper clips are the best option.
-Anna Sander, 15 April 2004
2013 update: another article on choosing the right archival fasteners! by Beth Doyle, a conservator at Duke University Libraries.
Conservation On-line Discussion List
Museum Management Program (U.S.A.) Conserve-o-grams
19.5 Removing original fasteners from archival documents
19.6 Attachments for multi-page historic documents
Northeast Document Conservation Center. ‘Preservation 101: an online course.’
NPO. ‘Good handling principles and practice for library and archive materials.’
Oxford University Library Preservation Services
Smithsonian Centre for Materials Research and Education. RELACT: ‘Basic handling guidelines for paper artefacts.’
UNESCO. ‘The education of staff and users for the proper handling of archival materials: a RAMP study with guidelines.’