Newsletter Issue Number:
AICCM National Newsletter No 160 April 2023
Author:
Kim Goldsmith

This article outlines the treatment steps taken to infill and inpaint losses to the extruded polystyrene (XPS) face and upper torso of the figurative sculpture entitled Waiting for another game by the contemporary artist Huma Bhabha.

Description

Waiting for another game is a three-metre tall sculpture. The figure has four faces and the upper body is carved from adhered layers of pink, green and blue XPS. This section is decorated in a graffiti-like style with fluorescent paints and oil sticks. The lower body and legs are carved from charred corkwood.

Condition before treatment, with losses.

Condition and damages

The sculpture had areas of loss on the XPS face, neck and torso caused by an anomalous incident involving a sugar glider grazing on these areas of the work. The areas of loss were quite deep, which was disfiguring to the overall appearance of the sculpture.

Face before treatment, with losses on proper left (PL) lower jaw, cheek and hair.

 

Detail of loss sites A and B on PL cheek, chin and hair (refer to image one).

 

Detail of loss site C on ribs, sternum and chest (refer to image one).

 

Detail of loss site H on PL neck (refer to image one).

 

Detail of loss site D (refer to image one).

Treatment aim

After consultation with the artist and NGA curators, it was decided that treatment was necessary because the losses around the face were too noticeable.

Analysis and materials identification

I contacted Huma Bhabha and she sent me a list of materials used to make the sculpture. She often uses found materials, so I undertook FTIR-ATR spectroscopy of the chewed fragments and confirmed XPS for the polystyrene layers and PVA adhesive bonding the layers.

Treatment challenges

XPS is a polymeric material that can easily be dissolved with solvents, so appropriate testing was conducted to ensure adhesives, fills and paints would not disfigure the original materials. Example case studies of fills for XPS were few, so I had to experiment with conservation and commercial materials to find a solution.

The sculpture had to be treated upright and offsite in a storage corridor. Working from a ladder to reach the top of the three-metre sculpture meant there were limitations to the types of materials I could use that would enable me to work safely.

Kim Goldsmith, Objects Conservator, NGA, working on the treatment.

Infilling

The texture of the sculpture is quite coarse and variegated, and so some of the areas  could be left without the need for filling or painting. It was too complex an undertaking to locate the original positions of all the XPS crumbs. After some tests I chose paper pulp as the fill material because it is lightweight like XPS, it can be textured to mimic the artist’s carving, and it is a conservation-grade material. A barrier layer of methyl cellulose was used, and the fill was a combination of paper pulp, methyl cellulose and deionised water. Toothpicks were used to texture the surface while the pulp was wet. I made a relatively dry pulp because the sites of loss were on a vertical plane and I had limited ways to prevent the fill from sliding while drying. A few layers were applied to account for shrinkage.

During treatment detail of paper mâché infill on sternum, textured with toothpicks.

 

During treatment detail of paper mâché infill on PL cheek and jaw.

Inpainting

To differentiate from the materials used by the artist, I chose gouache paints as my inpainting medium because they matched the matte appearance of the original paints. I painted a base layer of colour that matched the XPS (pink, green or blue), then stippled layers of black, green, pink and white over these areas, according to reference photos. I managed to make a close match to fluorescent pink using gouache that was slightly dull, so I added an additional layer of fluorescent acrylic paint.

During treatment detail of background colour on PL jaw, and stippled black and green inpainting on cheek.

 

Background colour and stippled matte paint to match original loss on sternum.

 

After treatment filled and inpainted PL side of face.

Results

From a distance, the overall infills and painted surfaces blended well, and the artist was sent before and after pictures of the treatment, with which she was very happy.

After treatment image of front face with fills and inpainting.

Future

Since this was my first experiment with paper pulp fills in polystyrene, I learnt that it is important to allow enough drying time between layers of pulp to make sure there is not too much shrinkage, and to spend time making sure the base texture and background colour are consistent with the original materials. I hope to do ageing tests on samples of XPS and the fills and paints I used to predict changes to the fills over time.