AIC's 52nd Annual Meeting

Soy-based ink is an increasingly popular material among contemporary printmakers. These inks are marketed as non-toxic, environmentally safe, and easy to clean using soap and water, making them an appealing alternative to traditional printmaking inks that require organic solvents and ventilation. The National Gallery of Art recently accessioned two large woodcuts on Japanese paper printed with Akua Intaglio® soy-based ink by Catherine Kernan [American, 1948– ]. Unlike traditional linseed oil or other vegetable oil drying inks that “dry” via polymerization, soy-based inks dry (for lack of a better word) by absorption into the support or interleaving. Kernan’s woodcuts were freshly printed when they were accessioned by the National Gallery, posing storage and handling problems as the inks were offsetting onto their interleaving, had a strong odor, and felt malleable to the touch. Not only is there no existing metric for how long a print made with soy-based ink takes to dry, the manufacturer of Akua states that “if there are any layers of ink that have not been pressed into the fibers of the paper, they will not dry” (Speedball Art Products Company, Frequently Asked Questions, 2023). This poster presentation explores the potential conservation and storage challenges posed by non-drying soy-based printmaking inks, and it outlines our observations derived from testing on two groups of mock-up linocut prints.

Both the mechanism for drying and the mechanical and chemical stability of soy-based inks printed on paper is unclear. Drying time depends on many factors, such as how thickly the ink is laid, how many layers of ink the printmaker applies, how the viscosity of the ink is modified using mediums, and the print substrate. As Kernan’s woodcuts continue to dry, we pulled two groups of mock-up linocut prints using Akua Intaglio® inks. One group was printed on Somerset, a thick Western cotton fiber paper, and the other group on Sekishu, a Japanese kozo paper. With consideration to the above factors affecting drying time, we made single-layer and multi-layer prints, single-color and two-color prints, prints with modified ink, and lightly inked ghost prints. Over several months, drawdowns with cotton swabs were performed to assess degrees of smudging occurring throughout the drying process. After almost six months, the mock-up prints had not dried appreciably. This finding led us to pursue scientific analysis of the proprietary ink formulation. With analysis, which will be undertaken by conservation scientists at the National Gallery (additional National Gallery co-authors to be added in the coming months), we intend to better understand the mechanism by which the prints dry and to identify the components that are left on the paper surface during and after drying. Finally, we will make recommendations for storage and handling of Akua Intaglio® ink prints.