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1. About The Lincoln Charters Project was launched in 2018 forming a partnership between the University of Lincoln and the City of Lincoln Council aiming to analyse and create a digital record of the collection of royal charters owned by the City of Lincoln. The project aims to use modern technologies to reveal as much information about the charters as possible as the collection has not been thoroughly recorded since Walter de Gray Birch wrote an account of Lincoln’s royal charters in 1911. Much of the collection has not been readily available to view since being placed into the Lincolnshire Archives in 1904 so the project also aims to make the information and documentation of the charters more widely available to the general public. This research focuses on one of the earliest charters from the collection, the Charter of King John dated 23rd April 1200. Exclusively non-destructive (where no parts of the object are destroyed, but small samples may be removed) and primarily non-invasive (where no samples are taken and the object is unaffected) tests will be carried out to provide information about the charter and allow conservation recommendations to be made. Allowing the charter to be understood and preserved for current and future generations to appreciate. History King John ruled England from 1199 to his death in 1216. He reigned at a turbulent time when the country was at war with France, royal treasuries were running low and the nobility were fed up with their lack of power. King John is most remembered for enacting the Magna Carta in 1215, reducing the power of the monarchy and increasing the rights and freedoms of the English people. This ‘Great Charter’ is seen as a pivotal moment in English history, however prior to 1215 King John had been providing sovereign grants to cities increasing the rights of their citizens. One such grant is Lincoln’s King John Charter of 1200 which affords rights its citizens not usually given outside of London and allows the city to elect representatives to represent them in Westminster. This makes the charter significant as it demonstrates the importance of Lincoln and it’s people to be granted certain rights before they were given to the whole of England 15 years later. John also granted a second charter to Lincoln the year prior however this does not survive in the Lincoln City Council collection. The charter is a significant piece of the local cultural heritage and provides a tangible link to Lincolnshire history. It is therefore important to preserve the charter for future generations. As well as making the object, in a suitable fashion, and the information learnt from it accessible to all. Transcription and Translation When writing the transcription Walter de Gray Birch also used the Charter Roll of King John in the H. M. Record Office in London as some areas of the parchment were too faded to comprehend Birch, 1911, p. xv). Both the transcription and translation can be found in Birch’s 1911 “The royal Charters of The City of Lincoln, Henry II to William III” on pages six to eight. Transcription (Latin) Translation (English)
2. Documentation Photography, Photogrammetry and Reflectance Transformation Imaging (RTI) have been carried out to create a thorough digital record of the charter. This will allow the charter to be more widely accessed, increase accessibility for viewing and studying as well as reducing the need for handling of and risk of damage to the object. Photography All photographs of the charter were taken using a Canon ESO 200D Digital Camera by the MA conservation students working on the project: Eleanor Bennett, Joanne Creighton, Catherine Hovell, and Hajni Nagy. Dimensions: Photogrammetry This process involved taking a series of digital photographs equidistant to the object with areas of overlap between the images. These were processed using Agisoft Metashape to produce an interactive 3D model of the object. The models produced are less detailed than photographs and RTI but allow the object to feel more tangible to a virtual viewer. The realistic digital twin shows how curvature of the parchment and the depth of the impression in the seal. This process can be carried out using basic equipment and free software however there were some difficulties in implementation. The software had difficulty aligning the photographs especially as turning the charter over altered the position of the threads. A 3D scanner would be better able to cope with these complexities and produce higher quality results. Reflectance Transformation Imaging (RTI) To create the model a cameral was set in a fixed position facing the object. A series of photographs were then taken as a light source was moved in circles at varying heights around the object while remaining a consistent distance from the centre of the charter. This created a series of raking light images. After processed using RelightLab definition not visible in traditional photography or photogrammetry can be seen. Detail in the seal and the texture of the threads and parchment are visible as the light angle is adjusted. RTI also allows for other visualisations where the object is falsely coloured to provide further definition of details. If there were any fingerprints in the wax seal these would become visible using this technique. RTI requires significant setup and space to conduct but does produce quality informative results using free software. The information provided can inform a condition assessment and provide a useful detailed model for documentation. Figure: The charter of King John, 1200, recto. Figure: The charter of King John, 1200, verso. Figure: King John’s great seal, recto. Figure: King John’s great seal, verso. l1 l2 l3 w1 w2 w3 Direction Section Diagram code Measurement (Inches) Length Full l1 19½ Parchment l2 9¼ Seal l3 3½ Width Parchment top w1 6⅛ Parchment bottom w2 7 Seal w3 3 Figure: Photogrammetry model of King John’s great seal, recto. Figure: RTI model of the charter of King John in visible light, recto. Figure: RTI model of the charter of King John in norlmals visualisation, recto. Figure: Taking the photogrammetry photographs of the charter. Figure: Taking the RTI photographs of the charter.
3. Materials The charter is comprised of four main components: the body of the document, the ink, the seal and the threads. Multiple approaches for identifying the materials used were triangulated to enhance the credibility of the findings. Main Body The charter is written on parchment. This is made from animal skin which is chemically prepared, scraped and dried under tension. Identification methods: Observation with the naked eye and through magnification using the Dino-Lite digital microscope were used to identify features physical of the parchment. The weight, thickness and texture of the main body are indicative of parchment and pores are visible under magnification confirming the animal based origin of the material. The arrangement of these pores has been compared to known samples in an attempt to identify the animal the parchment is made from. The results from this, however, were inconclusive. FTIR analysis conducted at two parchment locations supports the observations. When comparing the waveform and peak values for the charter (figure) to the results for a range of parchments the analysis aligns. This means the charter of King John is comprised of the same organic compounds and is also parchment. Historical research informs us that parchment was commonly used as a writing surface in the late medieval period with sheep and cow being the most common sources in the UK. Sheep skin was often used for royal charters as only one side can be written on making it difficult to tamper with the document. These methods are not enough to conclusively identify what animal the parchment is made from. The only way to know for sure would be to conduct destructive DNA testing. As all types of parchment are cared for the same the information gained would not justify the effect on the parchment to make conducting this method worthwhile. Text The ink used to write the charter is iron gall ink. The ink is made from readily available inexpensive ingredients. Whilst recipes differ in ingredient ratios and preparation methods recipes typically involve combining tannins, from gall nuts, iron sulphate, and water. Identification methods: The dark brown-black colour of the ink observed is typical of iron gall and other inks. The Dino-Lite images show the characteristic brown colouring of iron gall ink deterioration. By being able to make connections between the charter and the Magna Carter (a contemporary example of iron gall ink on parchment) this adds validity to the observations. Results of the XRF analysis of the ink are shown in the table below. The use of iron gall ink fits the historical context of the object as it has been used for over 2000 years and was the ink of choice across Europe throughout the middle ages. Seal The seal is made from a combination of original wax, in dark green, and more modern wax, white, used to hold the seal fragments together. The original seal was made my mixing beeswax with pigments and, when heated, was pressed between two metal matrices to form the unique double sided design of King John’s royal seal. Identification methods: The FTIR analysis from readings taken at two areas of original wax matches results from known samples of beeswax. This demonstrates that they share the same organic compounds and confirms the seal material as beeswax. The FTIR analysis is supported by historical context. Pigmented beeswax was used for making almost all seals in the medieval period, including royal seals. The seals on the Magna Carta documents were made of beeswax. The Magna Carta was sealed using King John’s great seal just 15 years after the Lincoln charter. The pigments used in the seal are more difficult to identify. X-ray imaging of the seal shows the dense pigment particles distributed throughout the wax. The wax is green in colour which can be seen with the naked eye and more clearly through magnification. The green colouring suggests copper forms a significant part of the pigment. The most common green pigments used in England in the late medieval period were Verdigris and Malachite. These are both copper based compounds. The nonorganic elements present in the wax are shown by the XRF results below. Threads The thread is made from dyed double ply silk fibres. Silk is made by boiling and unwinding cocoons produced by silkworms. These are twisted together to form silk threads which are often dyed using a variety of pigments. The threads on the charter have been used to attach the seal to the document. The threads were embedded into the seal when it was formed and threaded through a hole the folded area at the bottom of the parchment. Identification methods: The double ply and s twist are visible without magnification but are easier to examine with the help of the Dino-Lite and a microscope with a Dino-Eye eyepiece. The magnified strands were compared to known samples of silk to confirm the fibres carried the same characteristics of smooth strands commonly oblong in shape. Identifying these similarities confirms the charters threads as silk. The FTIR analysis further confirms the identification of silk as the peaks show the presence of peptides. Silk was also a common fibre to use when sealing royal charters bringing validity to the age and origin of the charter. As the original pigment has faded significantly it is difficult to identify the silk’s original colour. Some areas of red and yellow remain but it is impossible to gauge how much these have altered from the original shade. Attempts at XRF analysis did not aid in identifying the pigments used as there was a too varied spread of elements making it difficult to determine which may belong to the original pigments and which are contaminants. To learn more about the techniques used to identify the materials see the Testing page.  Threads  Table  Parchment  Parchment faded  Table Figure: FTIR analysis of the charter’s parchment. Figure: FTIR analysis of various parchment samples (Boyatzis, et al., 2016). Figure: Charter parchment, recto. Figure: Difference in texture of the writing side and folded over ‘back’ of the parchment. Figure: Dino-Lite image of parchment pores [55x]. Figure: Parchment pores calf, left, and sheep, right. [45x] (Johnson, 2022). Element Concentration (%) Analysis Iron (Fe) 34.45 The high concentration of iron is to be expected when analysing iron gall ink. Rhodium (Rh) 31.40 Found in copper which was often added to iron gall ink mixtures. Ruthenium (Ru) 12.23 Found in copper which was often added to iron gall ink mixtures. Gold (Au) 9.18 Possibly unintentionally added to the ink during preparation or the parchment has come into contact with a gold object during its history. Rhenium (Re) 7.71 Found in copper which was often added to iron gall ink mixtures. Figure: Charter text sample. Figure: Dino-Lite image of ink, a [55x]. Figure: Dino-Lite image of ink, b [57x]. Figure: Iron gall ink on Magna Carta, 1215, a [30x] (Duffy, 2015). Figure: Iron gall ink on Magna Carta, 1215, b [30x] (Duffy, 2015). Figure: Charter parchment, verso. Figure: King John’s great seal, recto. Figure: King John’s great seal, verso. Figure: Dino-Lite image of detail in wax seal [45x]. Figure: Dino-Lite image of green pigmented wax seal [45x]. Figure: Dino-Lite image of green (original) and white (modern) wax [40x].  Seal a  Seal b  Table Figure: FTIR analysis of the original wax. Figure: FTIR analysis of beeswax (Heinzel, et al., 2023). Figure: X-ray image of wax seal. Element Concentration (%) Analysis Copper (Cu) 66.31 The high concentration of copper confirms the analysis of the other identification methods. Suggesting the pigment is likely Verdigris or Malachite based. Silicon (Si) 14.70 These elements are likely impurities in the copper compound pigment or possibly a contaminant of the beeswax. Aluminium (Al) 7.32 Magnesium (Mg) 7.10 Lead (Pb) 1.59 Iron (Fe) 1.44 Cobalt (Co) 1.01 Figure: Threads connecting the parchment to the seal, recto. Figure: Dino-Lite image showing some colour in threads [40x]. Figure: Threads exiting the bottom of the seal, recto. Figure: Dino-Lite image showing thread density [40x]. Figure: Dino-Lite image showing ply and twist [40x]. Figure: Dino-Eye image showing ply and twist [80x]. Figure: FTIR analysis of the threads. Figure: Dino-Eye image showing characteristic silk [80x]. Figure: Silk sample [80x] (Dyer, et al., 2018). Figure: FTIR analysis of hard and soft silk samples (Geminiani, et al., 2023).
4. Testing All tests carried out were non-destructive and only one invasive test was conducted to minimize effecting the object whilst gathering information. All testing equipment can become broken or contaminated so they need to be maintained and calibrated to ensure accuracy. Digital Magnification - Allows for detailed observations to identify features, e.g. pores in parchment and twist in threads with visible light and carbon based underwriting with infrared. - Equipment: Visible light Dino-Lite and infrared Dino-Lite microscopes. - Light (visible or infrared depending on the device used) is directed at the object. The microscope records what is reflected back. Fourier Transform Infrared Spectroscopy (FTIR) - Identifies organic compounds. - Allows materials of component parts to be identified, e.g. beeswax in the seal from comparing the results to a known sample. - Equipment: FTIR handheld analyser and Spectragryph computer application. - Infrared light is directed at the object which causes the bonds between molecules to vibrate. The analyser assesses how different molecules react to this energy to create a spectrum of wavelength information. This can be analysed to build a picture of what compounds are in the object. Several readings should be taken to demonstrate consistency of results. - This analysis ideally requires a comprehensive database to compare results against and it is difficult to analyse the readings without this resource. Microscopy (and Dino-Eye) - This is an invasive (but non-destructive) technique, as part of the object is removed. - Allows for very detailed observations at high magnification of a small part of an object to aid identification, e.g. identifying the silk threads. - Equipment: Compound microscope (for observation) and Dino-Eye microscope eyepiece (for recording observations) - A sample is mounted on a slide. This is placed in the microscope and lit from beneath. This allows eyepieces, with various magnifications, to view the slide. The Dino-Eye replaces one of the eyepieces in a compound microscope to allow the microscope view to be captured and digitally recorded. Knowledge on how to use a microscope is crucial for producing clear images allowing for clear observations. Multispectral Imaging - Shows detail not observable under visible light such as deterioration factors of iron gall ink and possible underwriting. - Equipment: Standalone Crime-lite imager. - Light of varying wavelengths are directed at an object. The light reflected back is captured by a filtered camera lens. Depending on the wavelength, users must be aware of health and safety concerns as well as how to effectively operate the equipment. X-ray Fluorescence (XRF) - Identifies non-organic elements. - Allows materials of component parts to be identified, e.g. iron gall ink, from knowing the iron content of the text. - Equipment: Bruker S1 Titan handheld analyser. - The analyser is held close to the object’s surface, x-rays are emitted exciting the electrons in the object’s atoms. This change in energy is read by the analyser allowing it to determine the elemental components in the object. Several readings should be taken to demonstrate consistency of results. Using the analyser requires knowledge on how to use it, interpret results and the health and safety concerns associated. X-ray - Primarily used to identify metals but other materials can also be visible. - Could have provided hidden information about past treatments, such as pins in the wax, however little information was gained from conducting this testing. - Equipment: Faxitron 43604N X-ray System cabinet (at 15KVP for 20 seconds) and Agfa CR-30 Digitiser. - X –rays are passed through the object in the cabinet. The pattern of X-rays that pass through the object are recorded on the plate. This specialized piece of equipment requires an understanding of how it is used and the health and safety concerns associated with the radiation. To learn more about the application of these testing methods see the materials page. Figure: Using the Dino-Lite on King John’s charter. Figure: Dino-Lite image of parchment pores [55x]. Figure: Infrared Dino-Lite image of possible underwriting [30x].  Seal a  Seal b  Table Figure: FTIR analysis of the original wax. Figure: Removing a thread sample from the charter. Figure: Viewing the thread using a compound microscope and Dino-Eye eyepiece. Figure: Conducting multispectral imaging of King John’s charter. Figure: Using handheld analyser to take readings of King John’s charter. Iron Gall Ink XRF Readings Element Concentration (%) Iron (Fe) 34.45 Rhodium (Rh) 31.40 Ruthenium (Ru) 12.23 Gold (Au) 9.18 Rhenium (Re) 7.71 Figure: Placing King John’s charter in the X-ray cabinet. Figure: Digitising the X-ray image. Figure: Charter X-ray. Figure: Charter X-ray inverse. Figure: Multispectral image sequence.
5. Condition Condition Report Overall the charter is in a good stable condition. There is minor surface and structural deterioration but nothing that threatens damaging the object further if no action is taken. The surface of the object has some slight dust and debris. This dirt has particularly collected in the threads. The text shows some signs of fading and slight deterioration of the ink. This has been caused by storing the charter under unfavourable environmental conditions such as too much light . The ink is not significantly deteriorated as this would have been visible in ultraviolet light when multispectral imaging was conducted. The parchment shows signs of deformation as the material has curled up after being stored at an incorrect relative humidity (RH). There are some holes, losses and tears caused by physical force and handling, this problem was likely exacerbated by the parchment becoming brittle after being stored at a too loo RH. There is evidence of previous treatments. An adhesive paste is visible on the back of the parchment where it was previously attached to another piece of parchment. There are also tabs demonstrating another later mounting method. Reinforcement of weaker areas and gap fills have been carried out using Japanese tissue at some point since 1911. The wax has cracked sustained losses. Similar to the parchment the wax has become brittle whilst in storage and was more easily damaged when handled. The fragments of the seal were joined together with another wax at some point in the last 100 years. The threads have loose and fraying fibres caused by physical force and handling. Treatment Proposal It is recommended that preventative treatments are prioritised and remedial treatments not carried out. If they are deemed necessary remedial treatment should be minimal and professional conservator should be consulted. Preventative Store the charter in monitored non-fluctuating environmental conditions. Provide extra support for the charter whilst in storage, particularly to prevent the seal moving and distorting the threads when hen the draw is opened and closed. A ring of Plastazote or other conservation grade foam could be used to achieve this protection. Reduce handling, and transporting the charter. Ensure the storage building has emergency procedures in place and staff are trained to respond appropriately so the risk of significant damage to the object is reduced. Back up all digital records of the charter offsite. Remedial If Handled/Transported To reduce Handling/Transporting Handling - Wear nitrile gloves. - Use two hands, one to support the parchment and one to support the seal. - Use a tray and/or a trolley. Figure: Trolley and box used to move object to reduce handling.. Transporting - Consider custom packaging. - Ensure the way is clear and there is somewhere clear to place the object. - Ask for help to open doors, particularly if key accesses is necessary. - Ensure all moves serve a purpose. - Utilise the digital record so people can access the charter without moving it. Figure: Debris in the threads [80x]. Minimum Maximum RH (%) 55 60 Temperature (°C) 16 20 Light (lux per day) N/A 33 Method Advice Cleaning - Use and air puffer to gently remove any surface deposits. - Avoid using anything that would contact the surface. Humidification - Humidify the parchment to uncurl and flatten. - Use cold moist air in a humidification chamber containing the parchment only or a preservation pencil on a low setting. - Do not use damp blotters as this poses unnecessary risk to the ink. -The parchment is likely to curl ahain in the future if flattened so determine whether the treatment serves a purpose before going ahead. Removal of tabs - Attempt to gently humidify the tabs to loosen the adhesive, e.g. using a preservation pencil on a low setting. - If this gentle approach does not work reconsider whether the increased risk of adding moisture to the parchment makes the treatment worthwhile. Figure: Area of faded text that is no longer legible. Figure: Curved sides of parchment. . Figure: Curved edge of parchment and gap fill. Figure: Mounting tab, evidence of adhesive paste and past repairs, verso. Figure: Cracks in original green wax and visible repairs with white wax.. Figure: Loose silk fibres.
6. Bibliography Birch, W. de G. (1911) The royal charters of the city of Lincoln, Henry II to William III, [ebook]. London: Cambridge University Press. Available from https://eds-p-ebscohost- com.proxy.library.lincoln.ac.uk/eds/ebookviewer/ebook/ZTAwMHh3d19fMzUzMDUwX19BTg2?sid=2f e380ab-bd59-4483-b555-1bee4eb0fcad@redis&vid=0&format=EB&rid=1 [accessed 18 May 2025]. Boyatzis, S. C., Velivasaki, G. and Malea, E. (2016) A study of the deterioration of aged parchment marked with laboratory iron gall inks using FTIR-ATR spectroscopy and micro hot table. Heritage Science, 4, 13. Available from https://doi.org/10.1186/s40494-016-0083-4 [accessed 18 May 2025]. Duffy, C. (2015) British Library Collection Care blog: Under the Microscope with Magna Carta. Available from https://blogs.bl.uk/collectioncare/2015/07/under-the-microscope-with-magna- carta.html [accessed 18 May 2025]. Dyer, J., Tamburini, D., O’Connell, E. and Harrison, A. (2018). A multispectral imaging approach integrated into the study of Late Antique textiles from Egypt. PLOS ONE. 13. Available from https://doi.org/10.1371/journal.pone.0204699 [accessed 18 May 2025]. Geminiani, L., Campione, F.P., Canevali, C., Corti, C., Giussani, B., Gorla, G., Luraschi, M., Recchia, S. and Rampazzi, L. Historical Silk: A Novel Method to Evaluate Degumming with Non-Invasive Infrared Spectroscopy and Spectral Deconvolution. Materials 16, 1819. Available from https://doi.org/10.3390/ma16051819 [accessed 18 May 2025]. Heinzel, M., Kluge, E., Kemper, D., Schillinger, B. and Stieghorst, C. (2023) Metal 2022 Book Digital M Heinzel, Metal 2022 Proceedings of the Interim Meeting of the ICOM-CC Metals Working Group. Helsinki: Finland. Available from https://www.researchgate.net/publication/367348047_Metal_2022_Book_Digital_M_Heinzel [accessed 18 May 2025]. Johnson, A. (2022) University of Southampton Special Collections: V is for Vellum. Available from https://specialcollectionsuniversityofsouthampton.wordpress.com/2022/11/02/v-is-for-vellum/ [accessed 18 May 2025].