Good afternoon, everyone. Lovely to see such a strong audience today.
My name is Mahina. Listen, I'm the head of conservation and Heritage Things, which is a third of my type that's been recently acquired.
Although that's quite a new position in the conservation department, where heritage science sits in the country libraries.
We have been delivering scientific analysis, non-destructive scientific analysis of our collections for 12 years,
and that started with the power back in the day when we moved into the woods, even as a as a department, as part of special collections.
We have been operating on our income generating phases and of course the pandemic leaving around a little bit of flow of work.
But we have been revamping the heavy science department very recently,
and it is my pleasure to introduce you to Dr. King, who is actually a film and heritage scientist.
And he she's going to be offering this lecture which focuses on the analysis of pigments on the material and Japanese manuscripts,
and it's in particular about some specific periods.
Will tell you more about that. Just to say that during these 12 years of very good science that we've been collaborating with many other institutions,
scientific departments at the Metropolitan Museum, Durham University, also National Trust to name just a few, in particular with Durham University.
We've been working with thin pigment pigment, who is composed,
formed by two of the professors of Durham University, professor and Professor Richard Fields,
and both of them for only ten years have been analysing the pigments of the British and have four manuscripts in particular,
sort of focusing on medieval and renaissance manuscripts.
And that work has been in very, very close collaboration with public libraries because of the collections that we have.
So we continue that collaboration. We are making sure that that will last a bit longer and that there will be funding and
equipment and the lot of expertise to be able to continue delivering that kind of work,
which so far has been incredibly successful.
So we have a very, very good map now and a very good idea of the statements presented in British manuscripts of this piece.
Now, I sent you my Japanese.
That's what keeps one year of time within the volume with us when we focus, you know, has been focusing on and will continue to do so.
She will unveil how as seemingly unrelated bits of work are connected in one project.
But they are important to us because they are part of the larger.
So there's a larger picture to this. It's not just an audience and both within the Japanese library and with and in fact,
Alison and Keith, the Japanese librarian and other colleagues in conservation,
we've been studying the Japanese manuscripts and the Japanese collector for some time is quite spokesman to that sort of work.
And also with Byzantine manuscripts,
we have not been actually paying much attention to those in terms of analysis of the kind of So we, we wanted to start of the work.
So the emphasis is on that I'm sure is going to explain all about her work to make it quite interesting.
So there you have the lecture, so I won't give you any longer, but it was nice to see you all here and I hope you enjoy the lecture.
I think that was a really nice introduction. So, yeah.
My name is Kate and I am the new heritage scientist here at the Portland, based in Special Collections alongside conservation and my visits,
everybody, and as Virginia was just saying, is to analyse the pigments on painted Byzantine and Japanese manuscripts.
And so in this talk, first and based on some of the analysis methods that I use,
and then we're going to have a look at some of the examples I've been studying.
So the main piece of analysis equipment that we have here at the library is a hyperspectral imaging system.
And this technique was developed by NASA's Jet Propulsion Laboratory in the seventies and eighties and was
originally developed for the mining industry because it can identify different minerals over a large area.
And this is a picture of a sensor mounted on a dragon, which is how you would see very large land areas nowadays.
I mean, everything is on a plane and it has since been adapted for use in many applications, including agriculture last inland Atlantis,
the effects of pesticides, some crops and waste sorting because you can identify materials through processing.
Again, you identify and for example, foreign material in your feed and astronomy, which is essentially an imaging space.
And it's also used by the military for surveillance and it is also used for historical manuscript research.
So since it is not mounted on Israeli assets, actually stay still and the manuscript is moved underneath it.
So I'm going to show this in a diagram format because it's easier to explain.
So in diagram format, it looks like this at the bottom,
we have a moving platform and we lay the manuscript on this platform and it moves under the light and the analyser,
the incoming light falls onto the manuscript and is reflected by the pigments on the manuscript and is collected by the sensor.
So different setups will collect different information.
But the one we have claims reflected light over the range 400 to 1000 nanometres, which is all of the visible range and pushing into the infrared.
As the manuscript leaves underneath the light in the centre, some with light.
If there's any lines, the system we have is able to collect intensity information for 284 spectral parts of each small area of the manuscript.
And that small area is 0.16 millimetres squared.
This is not to scale every 0.16 millimetre square.
We have 284 points of data to collect that across the entire picture.
The entire picture is scans and each point has 284 and spectral intensities collected.
And if we look at. 284 points.
The data plotted and it gives you a section and every province has a unique spectrum.
Say, for example, this is Smolt, which is a blue pigment.
This is another blue pigments. That's July and this is another pigment indigo.
So you can distinguish between the three blue pigments for any point on our picture from one loss of collected data.
In addition to hyperspectral imaging, we also have access to other analysis techniques.
Through our collaboration with the research group at Durham University, the Virginia mentions collecting pigments.
It has been working with the body and since 2013 they have developed special equipment which
allows them to take their instruments to various library computers to analyse manuscripts in situ.
See, the problem they developed with their project was that those manuscripts are not about to move out of those institutions.
However, the equipments available when they began their research was all desktop huge,
massive instruments and they did at one point move an entire Roman instrument into the cathedral,
which was I think about two days to IBEX, and then it took about three days to stabilise within the cathedral and then they could start using it.
So they have been working since the beginning of that project to create portable instrumentation basically.
And of course it's got better with time as they've learned more about what they need and,
and parts of it just got better over time and things and obviously computers got better as well.
And so now they have a range of instruments which fits with the case.
And they've also managed to play around with the powers of the instruments.
And so fibre optic reflectance spectroscopy uses light stuff,
fibre optics to do basically the same as hyperspectral imaging is just over a wider range
of wavelengths and they've managed to tweak it so that the light is coming through.
That is showing the manuscript is the lowest power you can get away with,
say to cause the most minimal amount of damage to the manuscript possible Roman spectroscopy or description.
And if all the spectroscopy measures the Roman scattering and the interaction of the incoming lights with the bonds and molecules,
and again it produces a fingerprint spectrum for each pigments and that use of lasers.
So the ones you can buy off the shelf are usually developed for use in sort of mining and soil research and things like that.
So they don't really care if they're laser is pretty strong.
But we have with are extremely precious than ancient manuscripts say they've managed again they've managed to tweak it so that the
power is a fraction of the commercially available instruments so that we're posing no risks to our assumptions and xrx measures.
The elements present in the pigments and is particularly good at identifying metal components, for example, the LED and LED light and used together.
These are complementary techniques.
Some pigments are more easily identified with reflectance spectroscopy and some respond better to Roman, but used together.
They're a powerful suite of analysis methods that can tell us most of what we want to say.
Why am I analysed in a two completely unrelated collections manuscripts and say for start the techniques for analysing them at the same say,
and as we develop our techniques that will be the same across any and painted manuscript.
And what we were interested in these two groups of manuscripts.
So it's been noted by various sources that Byzantine manuscripts have had significant losses of pigments.
This is not a problem in any way unique to this collection. This is noted by scholars across all Byzantine manuscript collections,
and because this collection is regularly used by noble leaders, it was thought it's important to investigate this problem.
From a conservation and analysis point of view. The Japanese collection has been a focus for the conservation team this year,
and two colleagues went on an amazing study trip to Japan to visit paper and ink makers about which they're giving a lecture.
And tonight he's come and the departments secured a large amounts of funding for
the conservation of a set of three scrolls telling a story of student achievement,
one of victory, and one of our colleagues is here today will be taking the scrolls to Japan for conservation treatments,
where they will stay for a couple of days. So if he wants to do a study, stop the analysis before that because they'll disappear for a while,
and then pigment studies of Japanese manuscripts on other types of objects such as woodblock prints.
So we thought it'd be a good prompt to gather some information about these painted scrolls and books.
So I'm going to start by looking at some Byzantine manuscripts. These all dates from the 11th, 12th actually to 13th centuries,
and some are thought to come from Constantinople or something, and some have been designated provincial,
although I think this is maybe based on style and they're handwritten in Greek on parchment,
and they all pertain to religious topics such as the Gospels or the knife of judgement.
Quality of manuscripts is quite variable, as you will see.
And some have lost a great deal of their paint, which is one of the things we use, questions we are interested in.
Whereas others are studying the condition. So let's have a look. We're going to start with some provincial manuscripts.
So not from Constantinople. And I'm Skip American to add one dates to the end of the 12th or the beginning of the 13th century.
It's very large this way and thickness wise, and it contains about 230 coins of pictures of the book.
There are two black candidates used Vermillion and Red Baker.
Only Blue used in this manuscript is indigo, and the green used on this manuscript is a mixture of indigo with ultimate so yellow,
which is usually referred to as the dark skin.
Tones are done using ochres and and organic, which is used for cutting eyebrows and throwing pigment things out here.
We're going to look at some pages of the book and then I'm going to talk about all these people so that think is ongoing.
And you can see that the loss of pigment is quite substantial.
That's the picture from the same book with the of the Queen Virgo, which is that mixture of indigo and augment and all the reds, that of a million.
The ochre used for the skin these indigo manuscript very six is much smaller and dates to the early 19th century.
The blue in this manuscript is lapis lazuli, and there is an organic pink purple is that made by mixing the organic paint with lapis lazuli?
Ochre is again used for browns and skin tones green and this manuscript manuscript is a copper green specimen Again, later.
And as Lord. 338 is a collection of bits and pieces which have been bound together, dating mostly to the middle of the 13th century.
Again, we have bags from the million acre lot as natural light is used for the play.
There is no green pigments used in the book, but when they needed greenish tint,
they used indigo skin is done with a mixture of civilian and white, and the red ink is again an organic red.
But the red text in the picture is familiar. Now let's take a look at some of the manuscripts thought to be from Constantinople.
This is a kind of Greek 86, which dates to about 1300.
It immediately say that this is at a high quality of detail.
Yet the pigments are the same. Except we also now have as you write.
Compositions and more complex.
But the range of pigments is quite small, but the banks, vermillion, ochre and organic for the blues classify as he writes and indicate.
This manuscript, which speaks to the end of the 12th century.
We occasionally get a bit of green, and sometimes these get mixed together as indigo ends up or.
This manuscript dates to the first half of the 12th century and is extremely well executed.
Satellite is here, used on its own, but will say mixed with white to achieve pale blue or yellow to get green.
In summary, in the Byzantine manuscripts at this time period, we have three please indicate, as you notice.
And sometimes they get mixed together and sometimes they get mixed with white to create of these.
And then greens are always a copper based green or Virgo, which is indigo, mixed and ultimate.
And we get these we've had some okay and then various things mixed together to
create some other colours and the skin is always a couple of million of whites.
And then we have our inks as well. I'm going to talk a bit more about the pigments because I've been trying lots of
pigment things out there and people aren't necessarily knowledgeable about pigments.
So let's look. Million is essentially used extremely wisely at this point.
And it's mercury sulphide. It does occur in nature as the mineral cinnabar, but it was also widely manufactures.
And we have various recipes for this and from the Middle Ages.
And just by heating mercury and sulphur together, which created a trade in sulphur and Mercury.
A mercury was also used in medicine. There was wine trading of these these things going on.
The OTC is a naturally occurring clay minerals containing iron oxide with attractive colours.
They come in red is greens, oranges and purples and they occur widely in nature.
Although the best deposits were highly valued and traded,
long distance indigo is the dye extracted from the indigo plant and was used very widely antiquity and all the way up to modern times.
Now photography. This is a picture of Malachite with, as you might say, Malachite is a copper carbonate that occurs naturally.
And, as you might add, is another type of copper carbonate which often kinds of insides.
And these can be mines and grounds, cheeses, pigments.
But several medieval recipes are known for the manufacture of other big green pigments that the best known the impact
of the oflice for Salt green and his instructions are to make VOCs into a paste composites covered in honey and salt.
He then says to pour vinegar or urine into the box and leave it, stain it, and leave it for a few weeks.
When you come back, the copper will have changed into green or blue. And I did this, these vinegar and this is the results.
I used to look at Copper Pike.
So the first picture is after a few hours, middle on, after a few days, and the last one after about two and a half weeks.
So that was me at home with a Tupperware.
That is the video making my green pigments.
And I did actually analyse these and they were an acetic acid.
Sorry, I capacitate unclip chloride and I'd say it's possible each time you see a clean copper pigment so they could be modified,
but it also could be one of these other range of copper green pigments.
There's quite a wide range of and people were more than capable of creating these, as well as digging up from the ground.
So it's difficult with this technique to be specific.
I can lay out the techniques on top to be more specific. I haven't always done that and I haven't always got around to doing that.
For all of these examples that often says copper green waxes, malachite, I've, I've, I've identified it as a nice.
Lapis lazuli is the blue portion of the Nazi white mineral that creates a very bright blue pigment.
It was on his mind in Afghanistan and traded all over the continent, reaching as far as England by the 10th century.
It was very highly valued, both for a long journey and its vibrant colour.
Now, a couple of times I've mentioned an organic red and there are a couple of options for the origin of this, and indeed both may have been used.
One is the matter, which is a plant that is native to Eastern Asia, the Mediterranean.
The main currents of matter are this have been uncovered. It's always extracted by soaking the beach in water.
The other possibility is an insect dying.
This can be extracted from the Camas insects living around the Mediterranean, which is the green area or from the Polish or Armenian cochineal,
which is thought to spread from Europe over to the Caspian Sea and all from Indian lake insects.
These red dyes contain distinctive grasses,
and they say they can be distinguished from matter using chromatography That would involve taking samples for probably sizeable samples.
Well, smallish but bigger than we would want to go with. And so we haven't done these tests.
So all we've got is the spectra.
These talk perhaps again, ultimately some DC organic pigments that have different appearances.
Can we? 36 We can see a reddish organic take on a purplish organically pigments secreted from these extracted liquids by depositing
the dye on an insoluble paste such as the resulting dye attached to powdered pigment is known as the lake pigment.
All of the black or dark brown inks I've looked at so far in these manuscripts have been in gold ink.
This is made by leaching the tannins out of the gold or hawthorn bark, mixing with iron sulphide, also known as vitriol and water.
Maybe a binder or thickener like garlic. That's interesting.
So the question of the flaking pigments in Byzantine collections, I don't think I've yet reached a conclusion.
In some cases it appears that all the points lost and in others all the blue is retained,
for example, in the stitching for the hair and places, all the those retained.
And then right next to it all the goes lost. Sometimes all the faces are lost and others one face is retained next to a lost face.
Sometimes large sections of paint missing, whereas on other photos the paint has worn or scratched.
Department is very variable in policy. Even within one manuscript, the pages are often very wavy.
And sometimes there are significant ridges and folds in the parchments.
As you can see, this one has significant patches and folds, and it still has retained its pigment really well.
And the best many manuscripts also have superior parchment than a softer wool title, and they also have far less losses of pigment.
So at the moment I suspect that the losses are due not to the pigments or the quality of the culture it's underneath.
I also found that Byzantine manuscripts were sometimes close to the stain to make them shiny,
which might look attractive but is less likely to retain pigment over a long period of time.
So let's make a final conclusion. But I'm pretty sure that the losses of pigment are down to the parchment.
And so moving on to Japanese manuscripts, these take a format of scrolls or small text,
and there are sections of writing followed by a painting, and then another section about another painting and stroke.
Say, this is the scroll that we mentioned earlier.
This is a conservation in Japan. It's a well known story about a girl who runs away from hurrying to escape.
The pictures and scrolls are larger than that book and send pictures because there's just more space and scope.
So I have used another feature of the hypersexual imaging which is forming a colour.
So you pick a pixel that has the spectrum of save a million and then the software uses algorithms
to work out which other pixels have the same spectrum and how highlights them all the same colour.
And you can end up with something like this, say where it's coloured blue is red land,
where it's coloured orange is the median and then we've got some organic ones in there too.
And if I see you and you can see you can get some quite nice details that this man's coat is painted in red light.
But then the details have been done in vermillion and circles, so you can see some quite nice detail that is sometimes hard to notice.
I. And we can do the same.
Please. So if I toggle between the picture, the colour, I can see that where the computer has coloured it blue,
that's where you have indigo mixed with whites. That's a pale blue.
Often the trousers of pale green than where it's indigo not mixed with whites.
White are dark indigo. If you see that man's coat at the top shade in France, that's a very dark indigo.
And then the other pigment we have here is Smolt, which is the bright blue pigment which is on the squares top, right.
Another complex picture and we can map colours here too.
You can see the edging on McGowan's back left has a slight bright blue case on it and you can
see that on some of the figures they used the million infrared light in the same figure,
a different detail. And if we seen then you can see it is actually quite close to detail.
For example, the reds are vermilion and orange in red light,
and there are two types of pink organic red Lake with white mixed in red light with white Nixon.
Now, I'd say in a couple of new pigments in the ring there. And so let me just quickly describe them.
Red light occurs. Nature is medium, but it's pretty rare.
So it was probably manufactured by heating at once. And I also mentioned Smolts, which is ground cobalt blue glass.
And it gives that bright blue and there's no that is not in Japan at this time.
And the like is from Afghanistan, which is northwest China.
It doesn't get any further.
Say that a bright blue is this is this smelt classic that's been can be monophonic or indigo mixed with yellow as you can see on.
This my. As you can see on this latest dress with the same background, bright green, it's malachite on her dress square that has leaf motifs.
That's done with a mixture of indigo yellow that's much more already colour.
So you get a different quality of colour. And the way they use the reds is quite interesting as well.
So red last and familiar tend to be used for large blocks of colour like undergarments or the actual cloak, whereas the organic reds,
which I called organic red to you for a reason, I'll tell you in seconds, was used to do the details on the gowns.
So what kind of science? Again, there appear to be two different organic growth links there, Spectra said.
As I was just saying, one of them is used to be the detail of the games.
You can see where it says gang threat to usually a down detail like a flower or some dots or something.
So this one down there to the left and some at the top there.
And then the organic,
from what I've called organic red one is used and it's darker and more of a move uni colour and that's used as more sort of edgy,
organic that it's not used for detail. They have very different spectra.
It looks very different to me.
And the red or pink one has a bump at around 560 nanometres, and that indicates that it's an insect based, pigment based dye.
So other scallions. Sorry, I just got a studying Japanese wax from a similar time period.
Have also said they can see two different types of organic pigments and they always describe one as purplish as well,
same as we have had and in fact another has recently been identified on Ukiyo e prints and
in the Portland Art Museum and insect dyes identified in several Japanese as a period,
paintings have shades of cochineal, so therefore it's likely that we have two red pigments, maybe one from Mata and one from insect eye.
And that's sort of an ongoing interest point for me. So I'll be investigating further and say, this moth again, an early appearance.
It seems that Indian luck was the red dye and led pigment used in Japan.
Interestingly, by the 17th century, of course,
the Americas have been discovered and the Spanish were very quick to capitalise on the trade of cochineal dye from South America.
So as I'm sure you know, Europeans were thrown out of Japan in the 1630,
but the Dutch continue to be allowed to trade with them from Dejima and Dutch wool and
garments dyed with American cochineal turn up frequently in Japan at this period,
especially in ceremonial and military contexts.
Part of the appeal, in fact, of the Mexican cochineal was it had bound very well onto protein fibres such as will and silk,
and it's known that the Manilla Galleons carried cochineal as early as the 1580s on their transpacific voyage from Acapulco to Manilla,
and the dyeing surrounded China in the 17th century. However, within Japan, traditional red textiles was not replaced by cochineal until 1869,
which indicates the cochineal was probably quite rare within Japan.
And it's very probable that the French cloth pictured here was brought here, having already been dyed a sort of finished product.
So we can't tell from the spectrum, but from the historical evidence, it suggests that with the insect eye we have is Indian black.
That is still the question on paper that if we look at another scroll and Zeeman can see that there are several hues of green,
which is done by mixing various amounts of yellow and white with malachite.
And there is also that much green olive coloured green movement, indigo and yellow.
And again we have two organic red leeks, we have smolts and now we also have, as you write,
a lot of such objects in the past and these Indigo comic books which contain a mixture of writing and painted pictures,
again we see a consistent set of pigments, blues or indigo.
And as you write, although in this books, the ascribed is used for the pale blue instead of the indigo being used for the pale.
They say they've mixed that as white with white and green and red vermilion and red led and the insect eye again.
And pink is the insect eye plus white. And as an old friend, which contained a red light.
I'm something else, but I'm not sure what it is. This site so far has found a fairly consistent set of pigments.
I went I didn't think I was just another misstep. So here we have large amounts of the pinkish colour in the background and also they add that
black for the purplish colour in the background and some nice details in the clothing.
So all the little blue details have been done with as you write and the lady in the.
Like the person in the pink with the star motif on the cloak.
And that's why I think those colours all appear organic insect for one Scott White in it and one just.
In summary,
so far I have found a fairly consistent set of pigments for Japanese manuscripts in the 17th century and within a manuscript or set of manuscripts.
I also used in a consistent way. So if a scroll uses red light white in colour, that would be consistent throughout the school.
So what have I not been able to say? This technique is not great at identifying yellows, so I can't yet say much about the eyes.
And I'm starting to get the impression that yellow is tricky.
There is the additional hope in the Japanese use a lot of organic plant based yellows and say,
turmeric and some other ones, and they don't necessarily have very different reflectance spectra.
So that this might be a technique to distinguish between these.
And actually I need to experiment with some other techniques a bit more, but it might not.
It is just very hard to distinguish between these things without using chromatography and chromatography in both samples.
So then I use that extra difficult question of how much do we want to know and and yes, get to get there.
But I will try try this some other things that at first whites as well are not easily
identifiable using this technique because they tend to just reflect like that.
So instead of getting a nice set that tells you about the pigment, you just get a bit of light from that.
And then there is this threat in the secondary issue that I mentioned several times.
So with advances in various instruments and advances in computing power,
some scholars have said that the Indian locked eyes can be distinguished from the cochineal dyes for their reflectance spectra.
So if my data is good enough and they skilled as a threat, then it appears that my insect eye from the Japanese manuscripts is black from India.
However, I think we would have to do chromatography to confirm that and at the moment there isn't a compelling enough reason to take samples from
the paintings and I'm still looking into how easy it is to distinguish all the different types of cochineal from each other as well.
I think it is possible, but I would I would want to confirm these things before we even contract it.
And the other problem is, as you see from here, for example, that the areas that are painted with these insect eyes are extremely tiny.
So they tend to, as I say, they tend to be used for the little details.
And so that's another level of difficulty if you don't have huge amounts of evidence for them.
And there's also some question about whether a lake was actually used.
You know, I talked about, as you say, an insoluble bass and absorbing the dye on space.
I've written several pieces that they suggested that no bass was actually used and they were
actually just using the dye powder and in a binding medium like dramatic or something like that.
And so that's another question I have yet to address but would like to the paintings that.
And that's it. Thank you very much for your attention. I'm.