Modern transparent papers, also known as tracing papers, require specific chemical and physical properties, such as translucency, cmoothness, and whiteness, which are produced by specially formulated compositions and manufacturing procedures. Ironically, these special formulations may in some ways render such papers susceptible to problems from damage and degradation, shile also making them particularly reactive to moisture and solvents that must be used in conservation treatments to correct these problems. In order to evaluate the effects of water and organic solvents on such papers, four research projects were designed to consider the variables of paper composition, properties, type of solvent, technique of application of solvent, and flattening. This paper summarizes finding on materials characterization, degradative effects of aging, and some effects of solvents used on transparent papers for stain reduction, humidification, and flattening. -- CAL