A conservator’s job often involves removing non-archival tapes which have been used for repairs; a letter of C. F. Gordon Cumming to John Murray from 1885, however, proved particularly challenging.
The letter had been taped to hold together the fragments into which the brittle paper had broken. Almost half the surface of both sides was covered in tape. When sellotape-like material degrades, the adhesive migrates into the paper, causing significant discolouration and deterioration. As you can imagine, self-adhesive tapes can be particularly difficult to remove, especially from a brittle paper.
An additional consideration was the letter’s iron gall ink. If exposed to moisture, this ink deteriorates and can blur the text.
The tape film was removed by heating with a small blower, revealing the sticky adhesive underneath.
The adhesive was then removed with cotton swabs soaked in acetone.
This left the letter in several fragments!
Next came washing and a calcium phytate treatment, which removes soluble acidity from the paper, reduces disfiguring stains left by the tape, and helps preserve the ink. As the ink was exposed to moisture during adhesive removal, this was necessary to help to stablilise the ink and prevent future blurring. The calcium phyate collates the free iron ions responsible for deterioration, and transforms them into a stable complex. In this state, no further deterioration of the ink can occur. A special pocket was constructed to keep all the fragments together during washing, to avoid further fragmentation and potential loss.
Once the washing and de-acidification treatments were complete, I reconstructed the letter. Because it was so fragmented and still brittle, I decided to trap the fragments between two sheets of very thin and highly transparentJapanese paper. This will keep the fragments together and reduce the risk of further disintegration in the future.
Although this letter will never win any beauty prizes, the conservation treatment has extended its lifespan and made it accessible to our readers, as well as challenging my tape removal skills!