Science and the Art of Conservation


Prof. John Drennan, UQ
This colloquium will be held in Parnell (07) 234 at 3 pm on Friday 29th May.

Prof. Drennan provided a particularly beautiful abstract, which you may view here. A summary of the text is given below.

The art conservator must be a combination of scientist, with a wide and current knowledge of characterisation techniques, an art historian, and detective and have infinite patience. More often than not they are dealing with a painting in which the artist has concentrated on the aesthetics of the painting rather than in the preservation of the work for posterity. On top of this, oil paintings are not static, chemistry continues and external atmospherics can influence the conservation of the original works.

Professor Drennan became interested in a particular conservation problem associated with 20th century artists. At the turn of the century, artists turned away from the traditional lead based white paints to zinc based paints. Zinc white became popular and as manufacturing improved, became the material of choice for many paint manufacturers. Based on zinc oxide, oil paints containing zinc were not toxic, were less susceptible to blacking and had a pleasing lustre. However in 2005, during the cleaning of Van Gogh’s “Les Alyscamps” disfiguring protrusions were observed that appeared to crack the paint layer. The protrusions were identified as an accumulation of zinc stearate and is referred to as “zinc soap”. Since this observation the phenomenon of zinc soap formation is proving to be a major concern in modern oil paintings and in some cases can cause very disruptive effects.

In this presentation Professor Drennan will set thescene of how modern electron microscopy tech-
niques are providing insights into how the reaction of zinc oxide with the oil, forms zinc soaps. The development of these techniques has led to the exciting situation where UQ hosted several samples of Van Gogh’s sunflowers for analysis. This is an ongoing collaboration with the aim to develop conservation
strategies for this iconic art work.

Science and the Art of Conservation – Prof. John Drennan from School of Mathematics & Physics on Vimeo.