Hello from the Getty Conservation Institute: Jackson Pollock’s Mural

Last week I met Yvonne Szafran, head of paintings conservation at the Getty Museum. She told me a little about the joint Getty Museum and Getty Conservation Institute (GCI) project to treat the iconic Jackson Pollock painting Mural from Iowa State University. The painting was commissioned by Peggy Guggenheim in 1943 and is widely recognised as having a crucial influence on the development of the abstract expressionist movement.

Image credit: Tom Learner and Alan Phenix examining Jackson Pollock's Mural. Photo: © J. Paul Getty Trust. Art: University of Iowa Museum of Art, Gift of Peggy Guggenheim, 1959.6. Reproduced with permission from The University of Iowa.

Mural is absolutely stunning in the flesh with its dynamic layering of colour and the environment it creates due to the huge size (approximately 2438 x 6096mm). The painting is in good condition, but in the past it was varnished, which is at odds with Pollock’s technique, dust had settled on the surface making it dirty, another canvas had been adhered to the back (called ‘lining’), and it had been stretched onto a new stretcher (or supporting frame). The new stretcher is almost square but the painting is not, so unpainted edges are now visible having quite an effect on its appearance.

The GCI are using this opportunity to find out more about Pollock’s painting technique and to provide vital information to inform the treatment process. Several of the scientists have been involved, including Tom Learner and Alan Phenix, who you have heard about in my earlier blogs.

Currently the painting is located in a large table in the paintings conservation studio. It has already undergone several forms of analysis and been cleaned by conservators Laura Rivers and Lauren Bradley. The next step is to see if it can be safely restretched onto a new, sturdier stretcher that is better suited to support the great weight of the painting.

You can find out more information about this project on the Getty blog or see photographs and a video on the Wall Street Journal.

- Sarah Hillary, Principal Conservator

Hello from the Getty Conservation Institute – Paint layers

A tiny sample of paint embedded in resin can be made into a cross-section. They allow us to see the layering structure of the painting down to a microscopic level and we can analyse the individual layers as a consequence.

A cross-section from the painting Cross 1959 by Colin McCahon

 I have been making cross-sections for many years but wanted to improve my technique and Getty Conservation Institute (GCI) Scientist, Alan Phenix, agreed to show me the finer details of his method. Alan’s work at the GCI focuses on paint analysis, primarily to assist Getty Museum painting conservators with the paintings in their care.

Sampling from paintings is only done if absolutely necessary and great care is taken in finding a suitable location. The cross-section sample will be smaller than a pin-head and from an existing damage. Alan looks through the microscope to place the edge of the cross-section on a glass slide where it is secured. A plastic mould is placed around it, resin poured in and label inserted to the side.

GCI Scientist, Alan Phenix, pouring resin into the mould to prepare a cross-section.

The resin is placed in a chamber and cured by exposure from ultra-violet (UV) radiation for 25 minutes. UV setting resins are also commonly used by dentists today. Now the cross-section is ready for sanding and polishing followed by microscopic examination and digital photography.

Alan looking at the McCahon cross-section 

In the past the process of making a cross-section would have taken several days, where today we can get much better results in a couple of hours. Alan helped me to improve the surface of a cross-section from the McCahon painting Cross 1959 and he took a photo. Pity about the air bubble in the resin next to the sample, but I won’t make that mistake again!

The Getty will be publishing their cross-section technique online in the near future and more information about Alan can be found here:
http://www.getty.edu/conservation/publications_resources/newsletters/22_3/gcinews9.html

- Sarah Hillary, Principal Conservator

Hello from the Getty Conservation Institute – What paint is this?

When we talk about modern paints, we are referring to those based on synthetic media that were developed during the 20th century. For example, the binder in oil paints is made from natural vegetable oils, often linseed oil derived from flaxseed, whereas an acrylic paint is made from synthetic polymers manufactured from petrochemicals.

We generally rely on the artist’s description and close examination to get some idea of what paint it is. But the artist may not remember what paint they used, visual appearance can be inconclusive, and even if we did know what product they had used, the manufacturer is unlikely to reveal everything about it because of commercial sensitivities. So for an accurate assessment, it is necessary to do chemical or spectral analysis.

GCI Assistant Scientist, Herant Khanjian, with the FTIR microscope. The results from the analysis are on the computer screens behind 

While I have been at the Getty, we have been completing the analysis of some samples taken from paintings in the Modern Paints Aotearoa exhibition. The first we looked at were some tiny black scrapings that were taken from Stalagmites – Stalactites, 1964 by Theo Schoon. They are so small that you cannot see where they came from on the painting with the naked eye.

Image credit: Theo Schoon, Stalagmites - Stalactites 1964, oil on board, Auckland Art Gallery Toi o Tāmaki, purchased 1989 

GCI Assistant Scientist, Herant Khanjian placed a piece of the sample on a tiny ‘diamond window’ (a hard transparent platform) where it was flattened with a very small metal roller. The sample was then placed under the objective of the FTIR (Fourier transform infrared spectroscopy) microscope.

 The image of the sample on the diamond platform is projected on the front of the microscope 

FTIR uses the infrared radiation to analyse and produce information in the form of a spectrum (or chart) that is characteristic of the sample components. In the spectrum are bands which represent chemical bonding between two particular atoms or group of atoms in a molecule. The information is compared with spectra of other known material for identification. The results were a little confusing so we also did a solvent extraction. This means that a solvent was dropped on the sample to draw out the organic components which were analysed. The results were a lot clearer this time, and it appears that the paint is oil and alkyd.

You can find out more about Herant Khanjian here: http://www.getty.edu/conservation/publications_resources/newsletters/13_2/gcinews10.html

- Sarah Hillary, Principal Conservator

Hello from the Getty Conservation Institute – Lacquer Projects

On Monday I had lunch with two of the visiting scientists who have been contributing to the Getty Conservation Institute study into ancient lacquer finishes, Julie Chang and Ulrike Kerber. I managed to show my ignorance about this topic very quickly by asking about the use of shellac! I soon learnt that lacquer is nothing to do with shellac. Shellac is a resin secreted by an insect, but lacquer is based on sap collected from trees of the Anacardiaceae family.

The sap is very difficult to collect, and all of the processes of manufacture, which require great skill, are incredibly time-consuming. Julie had found a Chinese document from the 1st century BC which complained about the waste of resources in this process, because a lacquer cup would take 100 men to make and a lacquer screen, 10,000. The sap dries to a layer which is so tough that it can outlast the wooden structure that it is applied to. Many different processes were used to produce the traditional lacquers, but even with the subtle variation in end-product, it is still possible to spot a modern forgery.

Julie Chang with a lacquer cross-section on the screen

More information can be found on their website and the Getty is running workshops on the characterization of Asian lacquers.

- Sarah Hillary, Principal Conservator

Hello from the Getty Conservation Institute – Our Project

Kia ora from the Getty Conservation Institute in Los Angeles, where I am working for the next three weeks. Conservation Scientist Tom Learner, and I will be preparing material for the exhibition Modern Paints Aotearoa, which is scheduled to open at Auckland Art Gallery in April next year.

Auckland Art Gallery Principal Conservator Sarah Hillary and Conservation Scientist Tom Learner in the Getty Conservation Institute analytical lab.

The exhibition will examine the relationship between artistic innovation and painting materials in New Zealand art history, from the late 1950s until the early 1970s.

An understanding of materials is not necessary for appreciation of a painting, but it can provide a valuable insight into the artistic process because the choice of materials has a huge effect on what artists can produce. Big changes occurred in the New Zealand art in the 1960s at the same time as a range of new painting materials became available.

Acrylic paint samples in the GCI lab. 

The Getty Conservation Institute have been carrying out a study of modern paints for many years so that conservators will be better informed about how to preserve them. They have collaborated with conservators from many different countries during this time and the New Zealand project has involved staff from Auckland Art Gallery and Te Papa.

My next few blogs will look at the processes that we have to go through when identifying (or characterising) the paint medium and some of the other work going on here at the GCI.

- Sarah Hillary, Principal Conservator