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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. ABSTRACT-Contemporary tracing papers, also referred to as transparent or translucent papers, are produced by specially formulated furnish compositions and manufacturing formation processes that can make these papers reactive to solvents used in conservation treatments. An initial study to indicate areas of interest for further work was conducted. Four research projects were designed to determine (1) the various compositions and properties, (2) the degradative effects of aging, (3) some effects of solvents and techniques used for stain reduction and (4) humidification and flattening of contemporary tracing papers. Contemporary tracing papers can be characterized as transparentized either by fiber processing (overbeaten natural tracing papers) or by sheet processing, using either acid immersion (vegetable parchment papers); supercalendering (imitation parchment papers); or coating (vellum or prepared tracing papers). Although research is not yet complete, findings for this study indicated that aging resulted in the greatest change in color, opacity, and strength for a natural tracing paper sample, while solvent treatments resulted in the greatest increase in opacity in a prepared tracing paper, and humidification treatments resulted in the greatest gloss, transmission, and dimensional changes in an imitation parchment paper. JAIC 32(1993):177-206This content downloaded from 62.122.78.are produced by specially formulated compositions and manufacturing processes intended to achieve specific chemical and physical properties, such as translucency, whiteness, and smoothness. Special formulations and procedures may, however, render these papers exceptionally susceptible to surface marring, discoloration, and embrittlement. Tracing papers may absorb extraneous material such as adhesives, resulting in embedded stains that are difficult to remove. Often the papers are extremely hygroscopic, which makes them particularly susceptible to planar distortions and dimensional changes. Different manufacturing processes may also render the papers exceptionally sensitive to solvents used in conservation treatments (Baker et al. 1989). A review of the conservation literature indicates that the translucency of tracing papers may be affected by some solvents used for washing or deacidification (Flieder et al. ); by stain-removal (Flieder et al. 1991); or by humidification and flattening (Flamm et al. 1990; Hofinann et al. 1992; McClintok 1986; van der Reyden et al. 1992a, 1992b). To evaluate the effects on tracing papers caused by aging and by various types of solvents and solvent application techniques, several research projects were undertaken. This paper describes first the research design, followed ...

Experiments involving simultaneous comparisons of cells from two animals establish an age-dependent decline in protein synthesis. Specific radioactivities of fractions from cells of aged animals (20+ months) are depressed 60% to 80% versus those from younger animals (2 to 14 months). Isotope ratio patterns derived by PAGE indicate that formation of a 20000 MW polypeptide of cytoribosomal origin is even more strongly and specifically depressed.

Contemporary tracing papers, also referred to as transparent or translucent paPers, are produced by specially formulated furnish compositions and manufacturing formation processes that can make these papers reactive to solvents used in conservation treatments. An initial study to indicate areas of interest for further work was conducted. Four research projects were designed to determine (1) the various compositions and properties, (2) the degradative effects of aging, (3) some effects of solvents and techniques used for stain reduction and (4) humidification and flattening of contemporary tracing papers. Contemporary tracing papers can be characterized as transparentized either by fiber processing (overbeaten natural tracing paPers) or by sheet processing, using either acid immersion (vegetable parchment papers); supercalendering (imitation parchment papers); or coating (vellum or prepared tracing papers). Although research is not yet complete, findings for this study indicated that aging resulted in the greatest change in color, opacity, and strength for a natural tracing paper sample, while solvent treatments resulted in the greatest increase in opacity in a prepared tracing paper, and humidification treatments resulted in the greatest gloss, transmission, and dimensional changes in an imitation parchment paPer.