I knew very little about Richard Serra’s works on paper prior to Im Chan’s interesting presentation. She had the challenge of examining and housing a collection of Serra’s enormous oil stick prints at the National Gallery of Art.
First she explained how the prints were made using a combination of screen printing and oil stick. The oil stick itself was actually an adaptation of proprietary paint sticks that Serra would melt down, adding linseed oil and wax to make a large soft brick that could be drawn across the paper or pushed through a silkscreen, giving the print surface a thick texture. Im recreated the mixture and described it as being like butter. As an amateur artist, the idea intrigues me, but as a paper conservator, it sounds a bit horrifying! But I was impressed to learn that Richard Serra actually prepared his papers with a coating of Golden acrylic gel medium to protect the paper from oil penetration, and some prints even have acrylic gel between layers of ink. Naturally, however, there is some yellowing of the paper, and the media itself is also tacky.
The scientific analysis of her presentation dealt with the problem of the oils. She explained that oleic acid usually oxidizes to azelaic acid as it ages, but if it does not then the media will remain tacky and malleable, vulnerable to indentations and dust. The free fatty acids in the oils can migrate to the surface of the image and appear as cloudy efflorescence, marring the visual uniformity of the black ink field. She mentioned that when stored with cover sheets, many of the prints had transferred media and efflorescence to those cover sheets as well. Framed prints did not have glazing, and thus they were vulnerable to dust.
Im Chan’s work involved identifying and analyzing the problem, not actively treating all of the prints, and I could sympathize when she said it was difficult to resist getting her tweezers out to pick off all the dust and stray fibers stuck to the ink surfaces. She and her colleagues planned storage systems that would allow the prints to breathe, such as a box made of honeycomb board that had a sheet of microchamber paper across an opening in the lid to allow the exchange of air but to trap offgassing elements, having mentioned earlier that the prints had a strong smell of linseed oil, as I can well imagine!
Incidentally, the next day Joan Weir presented a talk on displaying another Richard Serra work on paper with some similar problems. It was quite interesting to hear her talk after Im Chan’s scientific presentation, so I already had a good understanding of what the artwork was like. That talk was:
(Contemporary Art Session 1) “When Conservation Means Stapling: Touring an Unsupported, Unglazed, 9ft x 21ft, oil paint stick on Paper to Three Venues” by Joan Weir.