A printed parchment document that I had recently cleaned and flattened was scheduled to be scanned prior to storage. I was not overly concerned with the possibility of dimensional change during the process, since the parchment would only be on a closed scanner bed for a few minutes. However, the large-format scanner was unavailable and the parchment was placed instead on a digital copy stand. After being left unsecured under hot lights during what seemed like countless minutes of preparation, the parchment began to distort in the top left corner.
Once I had the parchment safely back under weights and between felts, I contacted a colleague and arranged to borrow a suction table to re-flatten the parchment. However, I could only have the table for one day. The challenge was to find a way to humidify the parchment, a necessary step prior to the flattening process, without it spending at least one day in a humidification tank.
I decided to make a humidification “sandwich”, keeping the parchment document between felts and boards and in contact with a humidification agent. Although moistened blotting paper could be used for humidification, it would have to be wetted quite thoroughly in order to humidify the parchment quickly. Untanned skins do not react well to excessive moisture, especially if under pressure. Although blotting paper accepts moisture readily, it releases this moisture in an uncontrolled fashion.
I therefore decided to try Zorbix, since its superior moisture-loading capacity will allow it to absorb up to 50 times its weight in water. More importantly, the moisture is held inside the sheet and released as vapour so that the surface of the Zorbix sheet remains dry.
On the morning of the flattening, I spritzed four sheets of 15” x 20” Zorbix fairly heavily, placed them on either side of the parchment document between 3⁄4” wool felts with a protective sheet of Terylene between the felt and the Zorbix, and clamped boards on either side.
I then took the parchment to the conservation facility that housed the suction table, prepared the table and removed the parchment from the humidification sandwich. It was pliable and relaxed to the point where I was able to flatten it once again.
It will never look pretty – it has suffered too much for that – but at least it’s flat enough to be mounted in its custom-designed, buffered and sealed frame.
I have never had to humidify “on the fly” before, and hope not to have to do so again. However, the process was a success and I now have another use for Zorbix!
Jane Dalley is a British-trained paper and book conservator with 40 years’ experience, primarily in archives. She is based in Winnipeg and works throughout Canada and overseas. For some strange reason, she loves working with parchment.