The Preservation of Archive Records
11 October 2016
The Wargrave Local History Society's October meeting was an interesting illustrated presentation by Sue Hourigan. Sue has been conservationist at the Berkshire Record Office for about 25 years. Having decided that there was little prospect of progress in her initial occupation, she had embarked on a fine art degree course, although this too seemed to offer limited opportunities. She overheard several fellow students talking of conservation work, and decided that was something she could do, so took a course at Camberwell (which included the 'science' involved). The work at the Record Office involves both preservation and conservation of documents. She then explained the severity of what can happen to treasured documents, photographs, etc - not only in the official archives, but with the treasured collections people may have themselves, and some of the ways to look after them, categorising them into eight factors. The first was lack of housekeeping. There were several insects that could cause problems. She showed that a mounted WW1 photograph had been eaten into by silver fish, which are visible to the naked eye. In other cases, the cause of the damage might be less easy to see. Many older books had wooden boards - rather than cardboard - for the covers. Moths could lay their microscopic eggs, which, over the moth's five year life cycle, could produce larvae that would burrow into the covers. Another item Sue had brought to show the meeting was a water colour painting, which appeared to have foxing - brown patches - on the image. However, the discolouration was only on the sky (blue) areas, and not the land (green). The cause turned out to be microscopic book lice. One method to discover potential problems was to use an insect monitor - a sticky pad with a vanilla smell that would attract the insects where they would stick. A 'kills crawling insects' powder could then be applied as a preventative measure. The second problem was high humidity. Apart from encouraging the insects to grow and breed, it also made mould more likely to grow. A register dating from 1917 was an example of what damage could then be caused. It had become very damp, and the mould had broken down the structure of the paper. That in turn made it easier for book lice to survive on the fibres All 500 pages of the book had also stuck together, so the treatment involved separating each one before it could be conserved and repaired. The archivist's normal policy is to remove pictures or documents from any frames they are in, as there may be mould needing treatment hidden between the item and the back of the frame. The treatment for mould used to be to use thymol, but the process was not very effective, and the chemicals carcinogenic. The recommended process now is to use a smoke sponge, a latex which collects the dirt particles (the same process can be used to treat many other materials around the house). High temperature is a further hazard for documents. It can make mould reproduce more rapidly, but can also affect paints and inks. It has been known to soften oil based paint so that it sticks to the glass of a frame. In this case, Sue found, the treatment was to use heat again, in the form of a fine jet of hot air. This softened the paint in the way the problem had arisen, and so the glass and the print could carefully be separated. Exposure to light is a major risk to documents and photographs. They may fade in the light, but also the effect of light on ordinary card used for mounting items can cause the acidity in the board to cause a brown discolouration. Some papers contain lignin (part of the plant structure), which light affects making it become acidic from the day the paper is made. A particular problem Sue showed was a pastel drawing made on such paper - being a pastel, it could not be treated by washing to neutralise the acidity. Poor handling was another risk to old documents. Opening any old book stresses the binding, and simply supporting it on a cushion reduces the risk of cracking the glue or straining the binding. Another risk is where ancient documents have a seal attached. Often that is the most interesting part, but if double sided, tends to be handled a lot, so risking damage to the seal and its attachment to the parchment. Photographs are items which are also vulnerable to poor handling. Not only are they vulnerable to light, they easily get torn, and once the acidity in the skin left by fingerprints cannot be removed once it is on the image. One method is to image a digitally restored copy. The best way to deal with photographs was to store them in acid free polyester sleeves, so that they could be viewed without touching the picture itself. If these were stored in an acid free box, the photographs were then also protected from both light and dust. What Sue called 'do it yourself' was also another problem for documents. The kinds of adhesives available in a High Street stationer's shop could cause the paper to deteriorate. Sellotape, in time, becomes brittle, the tape itself separating from the page, and the adhesive leaving a brown stain, which permanently damaged the document. (Sellotape, she said, is "only for Christmas presents"!) Blu-tack creates similar problems. One particular example that Sue showed was of a 5m x 4m cartoon of a stained glass window design made by the artist John Piper. The pieces were joined with masking tape, and there was 'sticky back plastic' at the top and the back. It was not originally made to be kept for any length of time (John Piper being notorious for using 'anything available') but restoring and stabilising it for the future involved 150 hours painstaking work. Fastenings were a further hazard to old documents - especially plastic or metal ones. Staples, for example, would rust, and so not only would the document come apart, but the paper itself would be eaten away around the fixing. The last of the factors Sue listed was poor packaging. For most private collections, it was photographs that were most at risk of deterioration. The 'self-adhesive' type of photo albums, for example, would in time not only lose their grip on the pictures, which would fall out, but also the lines of glue would leave a permanent pattern on the image. For documents or books, suitable folders could be obtained - or made - from acid free card (and courses were available for those wishing to learn the necessary skills) to protect the items. Sadly, sometimes the damage becomes so severe that the item is fragile to the point it that it becomes unusable (and the information it had is lost for ever). In answer to a question, Sue said that although gloves cold protect documents from contact with skin, they resulted in a loss of sensitivity, so there was a risk of too much pressure being applied to the page. For velvet covered books or photographs, however, the use of gloves was advised. Sue concluded her practical advice by commenting that, for any document or collection, "if it's worth keeping, it's worth preserving".