Greek 19 & 20 are 2nd and 1st century respectively papyri fragments which had been rendered illegible by surface salt ‘bloom’. The items were required for study by Dr Roberta Mazza, Lecturer in Ancient History in The School of Arts Histories and Cultures. Roberta asked us what could be done to enable study of the pieces (Greek 20 is in 3 parts).
Advice about the reasons behind the salt bloom and apparent high moisture content (moisture droplets were visible on the inside of the glass) was sought from Bridget Leach papyrus conservator at the British Museum.
After consultation a treatment plan was proposed by Collection Care to re-house the fragments.
Prior to the re-housing work taking place, the Imaging Team were approached to see if they could capture images of the moisture and also to see if there was any way the text could be made more legible using digital technology.
The papyri fragments were digitised using the IQ180 and 120mm macro lens to obtain the highest quality images. Using careful focus control, it was possible to clearly see the water droplets as soon as the images appeared on the computer screen. We experimented with the levels and contrast settings and were able to very quickly render the text legible (however it must be noted that these adjustments produce inaccurate colour information).
The papyri were successfully re-housed using techniques used during a separate Arabic papyrus re-housing project.
When the two sheets of old glass were carefully separated the salt bloom remained on the surface of the glass. Samples of the bloom have been taken which will be sent for scientific analysis. We expect it to be sodium chloride. We suspect the high moisture content in the original glazing was probably due to “wet” paste used to adhere the leather strips which were used to seal the edges of the glass.
The fragments were then placed onto a sheet of UV filtered conservation grade glass, the edges of which are lined with 10mm wide acid-free paper of similar thickness to the fragments. This will ensure the glass is not pressing directly onto the fragments.
2mm wide strips of Japanese tissue are used to ‘tag’ the fragments onto the glass using a reversible adhesive.
The sandwich is then sealed around the edges using Tyvek tape and new identifying labels are adhered to the outside of the glass.