In papermaking, an alum bath refers to an aqueous solution of aluminum sulfate. The solution is sponged on paper prior to marbling. It acts as a surfactant and mordant to attract and bind the colorants to the paper.
Sources Checked for Data in Record
- Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982