Recreating the Medieval Palette: a workshop in Montefiascone

In July this year I had the opportunity to attend the Recreating the Medieval Palette workshop taught by Cheryl Porter in the picturesque town of Montefiascone, Italy. The five-day workshop consisted of lectures during the morning, followed by practical sessions of paint and ink making in the afternoon. The workshop allowed the members of the group to gain a deeper understanding of the history, chemistry and use of pigments that were produced during the medieval era, with a focus on European and Islamic manuscript art.

monte1

Left: Cheryl Porter lecturing. Right: A view of Lake Bolsena from outside the classroom.

During the workshop we studied two groups of pigments; organics such as indigo and madder, and inorganics such as gold and lapis lazuli. Inorganic pigments are further separated into natural or synthetic. Some synthetic pigments include vermillion, lead white, red lead and lead tin yellow.  We also had the opportunity to study inks including iron gall ink and carbon ink.

blues&ink

Left: Participants preparing the wonderful blue pigment lapis lazuli. Right: Experimenting with different inks, using a quill of course!

To create a colour for painting, the chosen ground pigment was firstly mixed with a small amount of water using circular motions in the shape of a figure-of-eight, to create a thick paste. At this stage the pigments were ground to the required particle size; some pigments need to be finely ground while others lose their colour if they are ground too much. Following this, a binding agent was added to the paste, to bind the pigment particles together and to help the pigment stick to the painting surface. In the workshop we tested a variety of different binding agents including egg white, egg yolk, and tree gums.

vermillion

Left: mixing egg yolk with Vermillion to produce a beautiful red colour. Right: the binding agent Gum Arabic.

For the medieval artist, understanding materials was a huge part of their knowledge and learning; they needed to know where to buy materials, how to make paint, how to apply their paints to specific supports such as plastered walls or parchment, and learn the skills necessary to determine their quality. For conservators it is useful to have an understanding of pigments and their chemistry to be able to make informed decisions when treating pigmented works of art.

I found it particularly useful to learn about the binding agents used in pigments. At the Chester Beatty Library I have been conserving a collection of Indian miniature paintings, which have particular problems with the lead white pigment flaking. Lead white was one of the most important pigments in the history of painting as it has wonderful density and whiteness; it was the best pigment for creating highlights. Chalk and bone were other options for white but they were often used as mixers only and their opacity was nowhere near as good as that of lead white.

lead_white slide

Left: Experiments using lead white. Centre: Adding water to ground malachite before the binding agent. Right: Grinding prepared pigment using a muller.

During the workshop I had the chance to prepare lead white and immediately I could see some of the difficulties in working with it. Firstly, most pigments are mixed with a small amount of water to create a smooth consistency before adding the chosen binder. However, as lead white is insoluble in water, this proved to be rather challenging- mixing it with a binding agent was more successful in creating a thick paste. Due to the density of the lead white pigment, large amounts of gum were added to create a smooth texture to paint with. The heavy lead and the large amount of gum Arabic binder added to the pigment often result in the flaking of lead white pigments on manuscripts. A new awareness of the historical and chemical problems with lead white has informed my understanding of the manuscripts I have been treating at the CBL. I now understand that many other pigments used in manuscripts were likely to have been mixed with lead white to create lighter colours, one of the reasons there are often problems with other colours flaking.

Lac slide

Top: Seed Lac. Bottom: Stick lac.

Learning more about insect colours was really interesting for me too (I am fascinated with bugs). One example is red lac, which is an organic pigment made from a secretion of the Kerria lacca or Coccus lacca insects that live on the ficus tree  and are native to India and South-East Asia. The word lac comes from the Sanskrit word meaning 100,000 due to the number of insects that live together. The insects secrete a waxy resin which can be harvested from the branches of the tree. This is referred to as stick lac.

Lac was an expensive dye used in ancient India, China and Syria, and then used in Western Europe by the Romans. It was often used as a lake and recipes are found extensively in the 14th century. The same material was also used for shellac and varnishes. Conservators must consider several factors when dealing with lac in manuscripts; the colour is very sensitive to pH as well as moisture. Additionally the red lac colour reacts to changes in temperature.

Unfortunately, very few organic colour keep their brightness as they tend to fade; also, they could only be used in season. Artists solved some of these problems by making clothlets. The process involved squashing the insects or plants until a juice was produced and then soaking up as much colour as possible with small pieces of cloth that were dipped into the extract. The cloth was left to dry and the process was repeated many times to get a saturated colour. When ready to use, a small piece can be cut off the clothlet and soaked in warm gum, which bleeds out the colour. Clothlets were fine for the manuscript painter’s needs, however they were not so good for an easel painter or someone who needed more bulk or covering power.

By the 14th century there was a technological leap and the most common way to preserve colours was to create a powder pigment from the colour juice or dye, which is called an organic lake pigment. The juice produced from the plant or insect could be poured onto chalk and then stored as a powder.

Lac prep slide

Left: Preparing a lac lake. Right: a small bottle of lac lake pigment.

The opportunity to attend this workshop in a beautiful part of Italy has been a fantastic learning experience for me. I was able to develop my knowledge of pigments to a much higher level and Cheryl’s lectures and instructions for making pigments and inks were not only informative but also a great deal of fun. As a variety of professionals attended the course including artists, conservators, students and historians, I felt I was able to exchange knowledge with other participants and learn more about the way in which this workshop was going to aid their work. By the end of the week, I had created samples on Islamic paper, European cotton paper and sheep parchment, which I will use as a reference guide when looking at pigments in manuscripts in the future.

I would like to thank the Zibby Garnett Travel Fellowship and the York Foundation for Conservation and Craftsmanship for generously providing funding to attend this workshop.

Puneeta Sharma, Heritage Council Intern in Paper Conservation

Advertisements

Wicked Wit: Conserving Mary and Matthew Darly’s Comic Prints

The conservation team have just completed a project to conserve over 140 hand-coloured, eighteenth-century etchings by the husband and wife team, Mary and Matthew Darly in preparation for the Library’s next temporary exhibition Wicked Wit.

This printer-publisher team produced well over 500 comic images of Caricatures, Macaronies, and Characters from no. 39 Strand (London) in the decade between 1770 and 1780. They became so popular that their publications were available throughout Great Britain and Ireland, Europe, and even America. The name Darly became synonymous with the humorous images they produced.

Wep 0494_disbinding (2)

The exhibition focuses on the largest album of Darly prints in the Chester Beatty Collection (Wep 0494). The 18th century binding contained 147 prints and was in very poor condition when it first came to the Conservation Studio at the beginning of 2015. Both boards of the quarter-back leather binding were detached, the spine leather was fragmentary with extensive losses, and the sewing was almost entirely broken. The prints were covered in surface dirt and a number had large tears and creases. Due to the level of damage that had already occurred to the album, and the risk of further damage to the precious prints it contained, it was decided to disbind the volume fully to allow for the conservation of the collection.

The decision to disbind an object is never one to be taken lightly, however in the case of this album, the extensive deterioration meant that disbinding the volume was the only option which would facilitate the safe conservation of the prints. It also presented a unique opportunity to display the folios as individual art objects in a dedicated exhibition before the eventual restoration of their integrity as a rebound volume.

repair

Once disbound, glue accretions were carefully removed mechanically before the prints were surface cleaned to remove dust and dirt with chemical sponges and localised use of polyvinyl eraser. Next, a number of large tears and losses were repaired with a range of handmade Japanese papers and wheatstarch paste. With the prints clean and fully repaired, they could be handled safely for photography and exhibition mounting.

As the prints will be rebound into an album after the exhibition, the mounting is a temporary measure, so the folios were secured in the bespoke conservation standard window mounts using Melinex V hinges. They were then framed in plain black wooden frames, which were sealed using paper tape; removing every fleck of dust and finger print from the glass is a surprisingly time consuming task for the team.

Darly slide

Hanging the framed prints is a precision operation and during the planning process a model of the gallery is used to work out the hanging for the room and calculate any additional temporary walls required. Curator, Dr Jill Unkel worked closely with the installation team to ensure the layout and order was correct, taking into account the positioning of text panels and labels. The conservation team then installed a number of bound volumes and mounted prints into four desk cases. Following a final clean of all the glass and touch up of the paintwork all was ready for the opening.

installation

The exhibition Wicked Wit opens to the public in the temporary Gallery on 11 September and will run until 14 February 2016. There is a richly illustrated catalogue to accompany the exhibition which is available to purchase from the Library shop.