4 CONCLUSIONS

We have described a method for the rapid production of fungal stains on paper. The ability to generate such stains facilitates the systematic study of stain removal and stain prevention and obviates the need to experiment on valuable artworks. Our initial results suggest practical approaches to the removal of the four fungal stains we examined: The purple-pink stain of F. oxysporum may be completely removed by the long-term application of 1,4-dioxane; the green stain of P. notatum can be significantly reduced by either 1,4-dioxane or N,N-dimethylformamide; and the yellow-brown stain of C. globosum can be significantly reduced by either 1,4-dioxane or N,N-dimethylformamide.

Our results dealing with the effect of pH, temperature, and light on fungal growth and stain production suggest conditions that will minimize fungal invasion: Storage of objects at 4�C should prohibit fungal gowth; treatment of paper objects with agents that will either neutralize acidic paper or produce slight alkalinity should significantly reduce fungal infestation. While the growth of the fungal species examined here is apparently not dependent on light, stain production by F. oxysporum is reduced in the absence of light; thus storage in the dark should inhibit stain production by this fungus in particular.

The work described here is a first step toward cataloging practicable procedures for fungal stain removal. Future investigations of stain extraction using other solvents and promise to provide paper conservators with an assortment of techniques for the effective treatment of paper objects damaged by fungal infestation. Moreover, the continued characterization of the effects of environmental conditions on fungal growth and stain production should reveal more defininitive guidelines for the prevention of fungal invasion.

ACKNOWLEDGEMENTS

We wish to thank the Samuel H. Kress Foundation for its generous support of this project; William Moomaw, Chemistry Department, Tufts College, Williamstown, Massachusetts, for many helpful suggestions; Nancy Piatczyc, Williams College for assistance with scanning electron microscopy; Gary Wolpert and J. Preston Clark, III, Crane and Co. Papermakers, Inc., Dalton, Massachusetts, for paper analysis; and Robert Futernick for helpful comments.