Conservation of Jasper Johns Decoy: Mold Removal Using Steam

Jasper Johns color lithograph Decoy, was printed by U.L.A.E. in 1971 on Rives BFK paper. Although printed with many colors, the image was predominantly black and disfigured by extensive white mold damage.

William Goldston, Director of U.L.A.E. and printer of Decoy was contacted for information regarding the print. He documented the printing of the lithograph and noted that the paper had not been pre-treated in any fashion, that the inking was the same for all colors and all passages, that no gums or surface varnishes had been applied, and that the intended finish of the print was a matt appearance. He specifically referred to several vulnerable areas: the lower six inches and the pinks that had little ink and mostly extender. The inks were resin based "Hanko" inks.

The damage to the print consisted of both white and smaller brown patches of mold. The white mold covered ninety percent of the print, although it was most notable in the black passages of the image. The bulk of the mold was removed by light brushing to loosen the mold and then vacuumed with light suction. The print was then sprayed with ethanol (Fisher A 407) overall. Many tests were done to determine an effective treatment some of which seemed promising. A combination of alkaline baths and ethanol applied on swabs, or a protease enzyme treatment all appeared effective in test areas. However, after treating the print with these methods, the print remained mottled with white mold.

The mold was again examined under magnification. It appeared to have a waxy body that held peaks and it seemed to be more on the surface and had not broken up the pigment. Tests with solvents (benzine, acetone, toluene/acetone) were not effective on the "waxy" mold.

Finally steam was tested locally and proved to be very effective. The entire print was treated in the following manner. A section was passed over with steam which wet the surface. The steam was passed over again and the area dried with cotton swabs. Apparently the swabs picked up the dissolved mold residue. When viewed under magnification, no residue could be seen.

The print was bathed in a final alkaline bath and dried between goretex, changes of blotters, and felts with glass as a weight.

It is uncertain why steam was effective in removing the mold, however it was very successful and should be considered as a treatment option.