Our ‘Medieval’ Wax and the Magical Aging Chamber

Filed under: Messing about in the lab — Hollie Morgan at 3:11 pm on Tuesday, May 2, 2017  Tagged , , , ,

As you might remember, a few months ago we spent the day in a lab using medieval recipes to make sealing wax. We had been careful to ensure that we had followed the recipes as closely as possible in order to replicate the methods used in the Middle Ages (ignoring the fact that medieval seal makers tended not to frequent state-of-the-art conservation labs…), but we were curious to know the extent to which our sealing wax was authentically ‘medieval’. Our friends in Conservation said they could help us with that, and so we took our wax over to a different lab, where we used a Fourier Transform Infrared (FTIR) Spectrometer to have a look at the chemical composition of our wax.

“What is a Fourier Transform Infrared Spectrometer?”, I hear you ask. Well, it is a clever machine that uses a mathematical model called a Fourier Transform to measure the absorption or emission of infrared by the material (in our case, sealing wax). The bonds between elements absorb infrared of different frequencies, which then causes them to vibrate. The FTIR spectrometer shines monochromatic infrared light onto the wax, records how much of the light is absorbed, and then repeats at different wavelengths until a complete picture can be formed.

FTIR readout for our red and green wax. The green line is red wax and the pink line is green wax (I tried, but I couldn't get it the other way around).

FTIR readout for our red and green wax. The green line is red wax and the pink line is green wax (I tried, but I couldn’t get it the other way around).

We can see from the readout that our red and green bits of wax had a similar composition, which is reassuring as beeswax and resin were used in both, but that verdigris and vermillion did make some difference to the ways in which the bonds were formed.

Our friends in Conservation then placed a piece of our red wax inside a magical Artificial Aging Chamber. An Artificial Aging Chamber uses heat and humidity to replicate the aging process, as warm, wet conditions speed up reactions. It is estimated that every 5-10°C doubles the rate of aging. Our wax was put in at 40% humidity and 40°C (any higher and it would have started to go soft) for about a month, and so was ‘aged’ by about 40 years. We then did some more FTIR spectroscopy. We compared the aged piece of wax to the unaged wax and also against a piece of wax from a seal of Richard II.

FTIR readout. Red=  unaged wax; Black= aged wax Blue= Richard II seal

FTIR readout. Red= unaged wax; Black= aged wax Blue= Richard II seal

As you can see, the black (aged wax) and blue (Richard II seal) lines are much closer together than the blue and red (unaged wax) lines. There is some variation, as we do not know the recipe used to make Richard II’s seal. This is an ongoing project, and we intend to continue aging our wax and analysing its composition, but we can see that as our freshly-made ‘medieval’ wax ages, it becomes more like ‘medieval’ wax as we know it.

Hollie L. S. Morgan

Behind the Scenes in Imprint

Filed under: Adventures in archives,Introduction,Messing about in the lab — Hollie Morgan at 5:44 pm on Wednesday, April 12, 2017

To find out more about what we’re up to, watch this video.

The Several Seals of Bella Hella

Filed under: Adventures in archives,Interesting Items,women — Hollie Morgan at 12:15 pm on Wednesday, March 8, 2017  Tagged , , , , ,

Today is International Women’s Day, and Imprint thought this would be a good time to tell you the story of a shrewd medieval businesswoman, from her first steps as an adult in her teens to holding an established position in her community.


In 1965 Francis Hill, writing on Medieval Lincoln, used some of the Dean and Chapter deeds to describe what was happening in the thirteenth-century Lincoln suburb of Butwerk. He described land in St Rumbold’s parish there ‘which once belonged to Matilda Drincalhut whose name suggests a street cry and its appropriate trade. Here too were Henry the illuminator, and Ralf the tailor’ (p. 161). All of this is true, but Hill ignores the person who is central to all these grants. When Imprint came to look at the deeds and the attached seals we found that the documents Hill used were all granted by one woman – Bella daughter of Alan Helle (once called Bella daughter of Alan of Glentworth) and that the sealing as well as the documents told us much more about Bella.

Bella’s father probably died whilst she was a minor, as the first grant she makes – to Henry the Illuminator of land once held by Matilda Drincalhut in the parish of St Rumowld –  includes an endorsement that she has made the document, being judged to be now in her majority, before the mayor and commonalty of Lincoln, when Roger son of Benedict was mayor, This is probably the first time Roger was mayor (around 1267, although Hill says 1275).

Excerpt from the dorse of Lincoln Dij74/2/3

Excerpt from the dorse of Lincoln Dij74/2/3

In two other grants of c. 1269, when William Holgate was first mayor, she grants more land in the parish of St Rumwold and land in St Bavon’s parish to the same Henry (very probably at the same time as the witness lists are near identical).

Each of these grants is in return for a halfpenny in lieu of service, but these halfpennies were then quitclaimed by Bella in favour of Henry for an even more nominal payment of a clove a year to Bella and her heirs, sometimes  1269-1273/4 (in one of the years that Holgate was mayor). This was not, though, the final piece of negotiation between Henry and Bella. Bella had retained a right in the property through the nominal service owed to her, and in 1275/6 (dated by the appearance in the witness list of Roger son of Benedict in his second period as mayor) the land in St Rumwold’s once held by Ralph the Tailor was re-granted, with identical boundaries, to Henry for 1d a year.

Two more, undateable documents also survive. In one Bella grants Henry the property in St Bavon’s mentioned in her 1269 document, but for an annual payment of 5d in lieu of service. There is also a more unusual document in which Matilda undertakes not to sell or alienate the property she owns in St Rumwold’s parish and with which she has enfeoffed Henry without Henry’s agreement. If she breaks this agreement, Henry is released form the 8s. a year he owes Bella at that point from property in St Bavon’s parish. Bella still gains in the short term at least in return for this this charter Henry has paid her twelve shillings sterling.

These seven documents show us Bella carrying out some shrewd business deals, apparently increasing in confidence over the ten or so years the deeds cover. If we look at her surviving seal impressions these also suggest a growth in confidence and status. Four of these seven documents have seals or fragments of seals on them, all of them according to the documents Bella’s own seal. They are not all, though, from the same matrix: Bella had at least three different matrices in this decade, and these changes both demonstrate something about Bella’s use of seals, and perhaps her attitude to sealing, as well as allowing us to place at least one of those undated documents in its correct place in the sequence of events.

Bella’s first document, the one issued when she was adjudged to be of age, has a round seal, with a simple radial design. The seal is in green wax, now repaired, what remains of the legend is nicely spaced, and the seal image appears to have been well carved if not of the highest quality. Such a simple design might well be what a young woman who finds herself needing her first seal might choose, and perhaps what she might be offered as an ‘off the peg’ matrix by an engraver.

Seal of Lincoln Dij74/2/3

Seal from Lincoln Dij74/2/3

The next sealed document, from 1269-c.1273/4 uses a very different matrix, a pointed oval, now broken but with an image which appears to be an inverted stylised lily, or possibly a cross shaped radial design (the missing bottom half of the seal impression makes it hard to be certain) with the remaining legend reading ‘+ S’ BEL … LLE’. This seal too is of reasonable quality, with the double LL towards the end of the legend nicely spaced – similar in fact to that of her first seal and possibly by the same engraver. It may well be that Bella was already using this seal by c. 1269: the pattern of the remaining tag on her two documents dated from round that year suggests it once held a seal which was a pointed oval.

Seal from Lincoln Dij74/129

Seal from Lincoln Dij74/1/29

By c. 1275/6, when she re-granted property once held by Ralph the tailor to Henry for a higher rate of payment than previously, Bella was using a third matrix. This was another pointed oval, again with a stylised lily image upon it, but this time a more elaborate one, and with a different legend reading ‘+ SIGILLV…BEL…’. This matrix was of higher quality, with a better engraved image and a well-carved legend.

Seal from Lincoln Dij74/2/1

Seal from Lincoln Dij74/2/1

Probably this matrix was also used for the last of Bella’s documents which includes a seal. This again is a stylised lily, of the same form, and the legend again starts +SIGIL … The impression is not as sharp as that in the 1275 document, and it is just possible that this impression is from a fourth matrix, but equally likely that it represents a careless use of the matrix or a matrix which has become worn. This impression is found on Matilda’s guarantee not to alienate her messuage in St Rumwold’s parish without Henry’s agreement so this can probably be dated to near the end of this run of agreements.

Seal from Lincoln Dij74/2/4

Seal from Lincoln Dij74/2/4

So as Bella gains in confidence and status she changes her seal matrix, ending up with a higher quality and a slightly more individual image.  Although these changes could be the result of lost matrices, the changes in style and quality suggest that Bella had made an active choice. Not all those who owned seal matrices changed them: even whilst changing their status and their description in their charters from daughter to wife to widow, women could retain the same seal. In such cases the owner’s feeling of identity with their matrix might lead them to keep it even as their life situation changed. In Bella’s case, however, it seems that changes in a matrix may be connected to changes in identity, revealing a different sort of relationship between sigillant, seal and matrix.

Philippa Hoskin

Fingerprinting as an Identity Science: A History

Filed under: Fingerprints,Introduction — foakes at 11:33 pm on Wednesday, February 22, 2017

As part of Aberystwyth University’s work placement scheme, AberForward, I was lucky enough to be placed under the direct supervision of Aberystwyth’s very own Lady of the Seals, Dr Elizabeth New, and work on the Imprint Project. I was incredibly excited to work on such an amazing project, although it did cause confusion with my friends and family back home when I told them that I was working on a project about medieval seals. (Surprisingly, a few thought I meant the mammal and were somewhat perplexed as to how medieval seals were different to their modern counterparts, let alone be able to work with a seal so old.)
A majority of the work I undertook was researching the origins and developments of identity science and fingerprinting. My goodness, it was fascinating! Shrouded with issues of race, the fear of the unknown, and even bickering ‘discoverers’, the development of using fingerprints for identification is definitely an interesting tale. Prior to the project, I had absolutely no idea how diverse its history is. I merely expected that fingerprints had been left at a crime scene one day and that the police inspector at the time had the bright idea to take all the suspects fingerprints and voilà! Fingerprinting had been invented. This was definitely not the case. It took roughly about a century to create a viable system which could efficiently deal with masses of information. For years, being able to identify people through their fingerprints was simply a dream and totally unrealistic. Thanks to the work of many including Sir William Herschel, Henry Faulds, Francis Galton, Juan Vucetich and Sir Edward Henry, the dream has become the reality.
Humans have always had a knowledge of fingerprints. It is nothing new. In Asia, Europe and North America there are cave paintings which feature fingerprints possibly showing authorship and/or identity. In China there has been evidence of fingerprint impressions in clay which were then used for official documents. The archaeological evidence found can be dated to the 7th Century but additional evidence suggests that this practice occurred earlier, during the time of the Han Dynasty (220 BCE – 202 BCE- so to put this in context, Rome was not even an empire at this period.) In the Holy Roman Empire during the medieval period, wax seals bore deep fingerprints, usually three in a line.
Prior to fingerprint identification, identity science was pretty limited. In a world changed by the industrial revolutions, many people were moving from the countryside to the city as well as moving up and down the social class scale. This made it very difficult to identify people based on who knew who and it became a society of strangers. It became increasingly important to identify those with a criminal record, since brandings had gone out of fashion, and society feared the ‘habitual criminal’, i.e. those believed to have been born to be a criminal and create mass havoc for the law-abiding citizens. At first, body marks (such as moles, birthmarks, freckles and scars) were used as the primary identifiers. However, it was quickly realised that it was quite easy to misidentify people as human memory is surprisingly rather terrible at actually remembering things. For example in Bangor, Maine, USA, in 1849 the parents of Luther Hause misidentified a man who they believed to be their son as the imposter was able to show scars on his knee, chest and neck which were what the Hauses could remember about their son.
Ideas to identify people could be pretty strange. For example, the use of phrenology (the deduction of personality and characteristics from the lumps and bumps of the skull which were supposedly responsible for specific character traits) and scent prints were both legitimate suggestions.
Alphonse Bertillon did create a system in the late 19th Century which was quickly adopted around the world. His system involved eleven precise measurements of the individual. Some of the measurements he took included the height, the head breadth, the left little finger, cheek width and left foot length chosen for their ability to not change due to weight. The coded descriptions, which involved vast amounts of information of the individual, were taken and included alongside the measurements with two photos on ‘Bertillon’ cards.


Arrest card, ca. 1933. 2006.488.106. Collection of the National Law Enforcement Museum, Washington, D.C.  From www.nleomf.org

Arrest card, ca. 1933. 2006.488.106. Collection of the National Law Enforcement Museum, Washington, D.C.
From www.nleomf.org

Fingerprinting was developed around the same time and became the accepted system of identification at the turn of the century. Bertillon’s measurement system was simply too complex and required considerable training, which many police departments had neither the time nor the money for. Bertillon required a level of exact precision which a lot of ‘Identification clerks’ did not bother to adhere to. They would often measure in imperial unit rather than metric (which Bertillon required for precision) so measurements changed from country to country thus creating inconsistencies. (The stereotype for Napoleon being a short angry man is completely false. Angry yes, short no. The French inch was much bigger than its English equivalent.) Fingerprinting required painting the individual’s fingers and thumbs with a special ink designed to make fingerprints more visible. They were pressed onto paper, and then sent to a specialist. Ta-dah! The individual was now in the system. The main problem was creating a viable system which could easily identify a set of fingerprints from a figurative ocean of millions.
The systems for fingerprinting were created in India and Argentina in the late 19th Century. At the time, the British officials were convinced that the Indians were prone to committing fraud (fraud was seen as the worst crime), and also believed that it was impossible to tell them apart, so it was possible they were pretending to be a dead person. In Argentina, crime and mass immigration were the main problems, because officials did not know whether the new immigrants were ‘habitual criminals’. In the late 19th century, Bertillonage was seen as the most sophisticated system whereas fingerprinting was deemed only suitable for the colonies because there were no natives who had the necessary skills for Bertillonage. (Racism was pretty normal back then.) Galton was the first to develop the system. He based his 3-point identification system on the work collected by Sir William J. Herschel, whose collection began in 1857 when he aggressively forced a building supplier to place his handprint on the back of a contract to avoid being swindled. Unfortunately, his system was not actually viable but luckily he inspired others. Vucetich and Henry both developed their systems from Galton’s and they both managed to create a fully functioning system which could cope with large amounts of data. This meant that it was finally possible to identify a person through a biological presence which was fairly unique for each individual.
I have thoroughly enjoyed my time working for the Imprint Project team. The work I have completed has been so fascinating that I will now be able to bore my friends and family silly from all the facts that I’ve learnt. My favourite aspect was being able to learn new and interesting facts about a period I am rather unfamiliar with, without the pressure of completing an exam at the end of it! I had quite forgotten the thrill of learning history for history’s sake. I will definitely be keeping up-to-date with the project and I would like to thank Dr Elizabeth New for allowing me to be part of it all!

Bethany Dale

Links and resources:
Simon A. Cole. Suspect Identities: A History of Fingerprinting and Criminal Identification. Cambridge, Massachusetts: Harvard University Press, 2002.
The History of Fingerprinting
Crime Scene Forensics, LLC

On Making Wax Seals; Or, Why Instructions Matter

Filed under: Messing about in the lab — Hollie Morgan at 2:38 pm on Monday, October 31, 2016  Tagged , , , , ,

A few weeks ago, members of the Imprint team donned white coats and headed for a laboratory to experiment with making sealing wax and applying seals to documents. The aim was to discover more about the material we are investigating, the physical process of sealing, and how and when prints on medieval seals were created, so that we can better understand and interpret the results of the forensic analysis.

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I have made sealing wax on numerous occasions, but usually in my kitchen (be warned that some of the ingredients are flammable or toxic!) and with appropriately medieval disregard for precise measurements, so I was particularly keen to have a clearer idea of exactly what was going on.

So, what did we do, and what did we find out? The principal ingredient of medieval sealing wax is… wax! Beeswax, to be precise: the hard, shiny sticks sold as ‘sealing wax’ are shellac (produced by a beetle native to South East Asia) or an artificial substitute. We used three different sources of beeswax and noticed that this affected the finished product, perhaps explaining why some medieval recipes specify ‘white’, ‘yellow’ or ‘polen’ (particularly high-grade) wax. Resin, usually colophony – Larch – is another key ingredient of most seals, making the wax harder, and pigment was often added.

‘Take a pound of whight wex, and throwe therinne a quartroun of terbentyne [...] Thanne loke thou have redy oz. 1 of vermyloun, smal grounde, al so smal as ony poudre’

 - BL Sloane 73, f. 173v

Based on fifteenth-century recipes in Trinity College Cambridge MS R.14.37 and British Library MS Sloane 73, we mixed beeswax, colophony and pigment at a ratio of 16:4:1, and found that it is important to keep stirring enthusiastically to ensure that the ingredients mix correctly. Beeswax starts to become plastic at around 32°C but melts at a much higher temperature, all recipes stating that the resin should then be added but not on direct heat, with pigment added last; our mixture was 69°C when the resin had melted and pigment was added.


‘sette it adoun of the fier, and styre it weel’

Having ruined one saucepan (only high-tech equipment for us!), we decided to employ a bain marie technique, but found that this does not work – the resin formed a hard ball amid liquid wax.


And that answers the question ‘Should we melt wax in the same way you’d melt chocolate?’. No.

So, armed with a new saucepan, we continued to experiment, adding vermillion (mercury II sulphide) for red wax and verdigris (copper II acetate) for green wax, as specified in the recipes.

It would have been impractical to go through this process every time a document needed sealing, and sealing wax was prepared in advance and formed into small ‘cakes’. The Trinity College recipe specifies that, when the wax mixture has solidified but is still warm, it should be ‘tossed’ between well-greased hands, rolled into a sausage, and sliced to form cakes. This is messy and fiddly, and during previous experiments I came up with an easier solution: pouring the liquid wax mixture into confectionery moulds.

This appeared to work, for although the pigment often sank, leaving the top of the cake pale, the colour  generally evened-out when the wax was re-warmed.





However, in the interests of science we decided to follow the specified method, and I confidently scooped up the warm wax mixture. I had, however, neglected another key point, and the wax stuck to my un-greased hands…


A fresh batch of wax mixture later and with grease (well, cheap vegetable oil) applied, the rolling was underway, and the resulting cakes were a consistent and bright colour throughout – so don’t try the shortcut! It would be interesting to know what types of ‘grease’ were used, and what effect this might have on the consistency and stability of sealing wax.


We knew we’d bought that vegetable oil for a reason…

Once the cakes had cooled and hardened, the next stage was to recreate the process of validatory sealing. Sealing wax can be applied to the face of a document but adheres poorly, and in medieval Britain the principal means of attachment was via a cord or strip of parchment hanging from the document. This requires wax to be moulded around the parchment strip or cord, and there are debates about how this was done. It is sometimes suggested that one wax cake was pressed into the matrix, the cord or parchment strip laid across this, and another cake then moulded over the top. This makes sense if a large matrix is impressed in one side of the wax and a smaller matrix in the other side, since it avoids damaging the impression from the principal matrix while the second is impressed – although Imprint has found several examples of hand and finger prints over the principal impression. A second theory, which from experiments and extant seals I think was most common in England and Wales, is that two cakes were moulded together and the wax disk held while a matrix was impressed. The initial findings of Imprint seem to support this, with numerous examples of clear and relatively deep palm prints on the back of pendant seals.

Before the wax is attached it needs to be warm enough to be malleable and take an impression, but not so soft that they it is difficult to handle or sticks to the matrix. I usually warm the cakes in water since beeswax is water-repellent (but they need to be dried carefully to avoid water damaging the parchment, and it is easy to scald your fingers dunking them!), and know from experience how soft the wax needs to be, but ‘this feels about right’ is hardly a scientific benchmark so we used a probe-thermometer for a more precise reading: 43.9°C in the case of our second batch of green wax.

14517359_979852002140760_5317345504860542485_n  14502867_979852055474088_9206955256314659932_n

The final stage of the process is to impress the matrix, and it is sometimes suggested that it was powdered or oiled to help with removal from the warm wax. I’m doubtful about the former because I have never seen pitting on an impression which could result from this, and rarely use the latter, but we decided lightly to oil the matrix. Holding the wax carefully on one hand I impressed the matrix with the other, something which takes a surprising amount of pressure. The result was a clear impression of the matrix and, on the back of the wax, visible lines from my palm, just as we so often see on medieval seals.


The experiments confirmed some things we knew, but also provided unexpected insights and led to further questions. Firstly, the process of documentary sealing is a complex one, and benefits from experience. From adding wax to a container and starting to warm it until the sealing wax cakes were cooling on the worktop took approximately fifteen minutes, but we were making very limited amounts and had the advantage of an electric heater. Furthermore, the fumes given off by the ingredients are strong (plus vermillion and verdigris are poisonous), and the preparation of large batches of sealing wax would have been an unpleasant task, perhaps explaining why even small scriptoria and chanceries appear to use quite a lot of similar-coloured wax at certain times. The importance of kneading the cooling wax mixture to ensure a consistent and vibrant colour was something of a surprise, and whether this was done, and for how long, may also be a contributory factor in seals of an inconsistent hue or grainy appearance, although the latter may also be the result of resin not melting properly – as we found out – or pigment not ground finely enough or added too late in the process.

Of perhaps greatest significance for the Imprint project were the final stages of the process, attaching the wax cakes to a document and impressing a matrix.


Although the cakes need to be quite warm when forming the disk, and despite the manipulation of the wax at this stage, there were very few, very faint, prints visible. It was only when holding the wax and exerting enough pressure to create a good impression of the matrix that my prints were clear. I deposit poor-quality prints, and women generally have lower ridge detail than men, but this does suggest that many of the prints we are analysing were made when the matrix was impressed, rather than at an earlier stage. We also found that, despite enthusiastic handling of the wax soon after the matrix had been removed, no further prints appeared to be deposited, again suggesting that those on medieval seals were made during the actual sealing process. Finally, I held the wax in my left hand, orientated with the parchment tag between my thumb and forefinger, because this replicated prints on several seals analysed for the pilot project.


Although it would have been possible for another person to impress the matrix, it is much easier for the same person to hold both wax and matrix. As we analyse more Imprint data we plan further replications of how the wax was held, since this will help us to study the physical process of sealing and its implications for questions of agency, participation in legal and administrative processes, and access to the enacting of power and authority. It will also give us an excuse to spend another fun day in a lab!

Elizabeth New

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