Foxing on Paper: A Literature Review

AbstractThere has been a large amount of research published on foxing formation. This paper reviews selected literature published between 1930 and 2003 to show the progression of the research approach on this subject and to suggest areas for further discussion and research. Metals and microorganisms have been considered the main causes of foxing formation. Scanning electron microscopy and elemental analysis for inorganic and organic compounds were the main tools for finding the presence of metals and/or microorganisms in foxing spots. Newer research has focused on the condition of the affected paper itself by measuring the amount of free radicals and different functional groups formed by oxidation or acid hydrolysis. Certain foxing spots were found not to be associated with the presumed causes, i.e. metals or microorganisms. As a result, new hypotheses have developed on foxing formation including preferential cellulose oxidation or moisture condensation related to the non-homogeneity of the paper. Suggest...