Glamorgan’s Blood Preserved on Glass

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The National Coal Board collection at Glamorgan Archives includes a large amount of photographic negatives on both plastic and glass supports.

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The glass plate negatives, approximately 5440 in number, feature a range of subjects, including images of tunnels, miners in action, equipment, pit ponies, medical centres, social events and other varied content.

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As part of the Glamorgan’s Blood project, this photographic material will be catalogued, cleaned, digitised, conserved and re-housed, allowing public access to these images.

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While the majority of the glass plate negatives simply need cleaning prior to digitisation, some display more extensive conservation issues.  A number of the plates are broken or have lifting or highly damaged emulsion (fig.5).  These issues will require more supportive housing solutions or more intensive conservation treatment.

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Figure 5

Undamaged but dirty glass plate negatives require cleaning prior to digitisation and re-housing.  Surface dirt on these items can contribute to long term deterioration and be visible on the digitised image.  It is important that the plates be properly cleaned before any further steps in the preservation process can be taken.

To clean the plates, first an air-puffer is used to remove loose dust and dirt on both the emulsion side and the glass side.  By using this tool, the emulsion side of the plate can be cleaned without risk of abrasion.  Next, cotton wool buds wrapped in fine tissue and dipped in a solution of water and ethanol (50:50) are used to remove dirt and grease from the glass side of the plates.  A final wipe, using a dry cotton wool bud, removes any streaks.

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Figure 6

The cleaned plates are then re-housed in folders made from material up to PAT (Photographic Activity Test) standards.  We use different sized folders for the varying plate formats to ensure a good fit (fig.6). The original packaging for these items was glassine envelopes, which is a type of highly calendared paper often found used for the storage of photographic negatives. Glassine is an inappropriate storage material as it yellows over time and can damage the photographic emulsion (fig.7).

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Figure 7

Once cleaned, the plates are scanned and a positive image is created.  This will then be added to the Archive’s catalogue.

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Figure 8

Broken glass plate negatives require housing which both supports the fragments but also keeps them separate to ensure the delicate emulsion is not damaged through abrasion between the glass shards.  The new housing incorporates cushioning plasterzote foam within an un-buffered card enclosure.  This new enclosure allows the negative to be safely stored and, if necessary, viewed without removing the individual shards (fig.8 & 9).  This simple housing solution can provide either temporary or long term storage, allowing for further repair treatment to be carried out in the future.

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Figure 9

The broken negatives will also be scanned and digitised, reducing the need for handling while at the same time ensuring public access to these wonderful images.

Stephanie Jamieson, Glamorgan’s Blood Project Conservator

Dealing with Mould

Last week it was brought home to us how important it is to have good storage conditions that comply with the relevant British and international standards. A box of documents had been requested in the searchroom by our Senior Archivist, and on production it was found that the documents had what appeared to be live mould on them.  At that point I was called in to confirm the finding.  Mould thrives in poor storage conditions with high relative humidity and high or low temperatures, feeding on the proteins in parchment and glue and the cellulose and size in paper.

The box of documents had been kept at an outstore with no environmental monitoring systems or controls. There were areas of damp and massive temperature fluctuations, all threats to long term health of archival material.  Poor storage conditions were a major driver for the relocation of the archive service in 2010.  Outstores had been needed since the 1960s as the former building was filled to capacity, and very few were ideal for the purpose. The good news is that once moved into stable storage conditions mould growth will slow down and eventually die, a process which can take around 5 years or more.  And we are entering our fifth year in the new building with the entire collection on site and in excellent conditions.

Checking boxes for signs of mould

Checking boxes for signs of mould

Just to be safe, other items and collections previously stored in the same outstore area as this box had to be examined. With help from  Amanda (one of our conservation Volunteers) and Mary (who is with us on work experience) I set off on a mould hunt So far we have found signs of mould in 30 boxes.. Once mould is found the box is removed to our isolation area where the mould can dry out before cleaning commences. This has to be done using specialist tools and wearing personal protective equipment as the mould, is not only very dirty but can also be hazardous to health.

Cleaning documents affected by mould

Cleaning documents affected by mould

Mould can be in the documents before they come to us and we now have a system (and the space) for checking all accessions and cleaning and packaging them before shelving them in the strongrooms.  The recent discovery was a reminder of the bad old days and an incentive to maintain new procedures.  Staff are currently checking all boxes in the collection to confirm location and contents.  Conservation needs are also being flagged with mould identification now a top priority.

Users and staff regularly comment on the benefits of being in a purpose built facility.  It’s good to be reminded that the documents needed the move even more than we did!