Historic Textiles, Papers, and Polymers in Museums In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. ACS SYMPOSIUM SERIES 779 Historic Textiles, Papers, and Polymers in Museums Jeanette M. Cardamone, EDITOR Agricultural Research Service, U.S. Department of Agriculture Mary T. Baker, EDITOR Egypt MVE American Chemical Society, Washington, DC In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. Library of Congress Cataloging-in-Publication Data Historic textiles, papers, and polymers in museums / Jeanette M. Cardamone, editor, Mary T. Baker, editor. p. cm.—(ACS symposium series ; 779) ISBN 0-8412-3652-6 (alk. paper) 1. Textile fabrics—Conservation and restoration—Congresses. 2. Paper—Preservation— Congresses. 3. Polymers—Conservation and restoration—Congresses. I. Cardamone, Jeanette M., 1959- II. Baker, Mary T. III. Series. TS1449.H58 2000 702'.8'8—dc21 00-058618 The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences—Permanence of Paper for Printed Library Materials, ANSI Z39.48-1984. Copyright © 2001 American Chemical Society Distributed by Oxford University Press All Rights Reserved. Reprographic copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Act is allowed for internal use only, provided that a per-chapter fee of $20.00 plus $0.50 per page is paid to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. Republication or reproduction for sale of pages in this book is permitted only under license from ACS. 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PRINTED IN THE UNITED STATES OF AMERICA In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. Foreword The ACS Symposium Series was first published in 1974 to provide a mechanism for publishing symposia quickly in book form. The purpose of the series is to publish timely, comprehensive books developed from ACS sponsored symposia based on current scientific research. Occasionally, books are developed from symposia sponsored by other organizations when the topic is of keen interest to the chemistry audience. Before agreeing to publish a book, the proposed table of contents is reviewed for appropriate and comprehensive coverage and for interest to the audience. Some papers may be excluded in order to better focus the book; others may be added to provide comprehensiveness. When appropriate, overview or introductory chapters are added. Drafts of chapters are peer-reviewed prior to final acceptance or rejection, and manuscripts are prepared in camera-ready format. As a rule, only original research papers and original review papers are included in the volumes. Verbatim reproductions of previously published papers are not accepted. ACS Books Department In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. Preface This volume continues the fine tradition of the American Chemical Society (ACS) of publishing papers from the symposia of Historic Textiles and Paper symposia sponsored by the Cellulose, Paper, and Textile Division of the ACS. Three Historic Textiles and Paper symposia have been published as ACS Symposium Series and two as ACS Advances in Chemistry Series. Two of the books were edited by Howard Needles and Haig Zeronian, retired Professors of Textiles of the University of California, at Davis. Needles and Haig have made significant contributions to the conservation science literature. In keeping with this tradition, this book is a tribute to the ACS for its promotion of the science base of fundamental investigations for historic works of art. This volume presents reports from two symposia: Historic Textiles and Paper and Polymers in Museums that were presented at the national ACS meeting in Boston in 1998. Within the symposia, investigators have examined unique character istics and analytical methods that have lead to proposed solutions for stabilizing aged protein fibers (wool and silk) and cellulosic fibers (paper and wood) as well as synthetic polymers. These investigators are practicing conservators, conservation scientists, and academic researchers. Their works add to the rich resource of conservation research that informs broad audiences of the unique challenges involved in investigating objects of historic significance. This ASC volume on Historic Paper and Textiles is an important ref erence for the application of scientific methods to examine artifacts and art objects and for the assessment of their condition. It can be used for formulating decisions concerning documentation, prescribed care, exhibition, and storage. It covers the aging of natural and synthetic polymers such as wool, cotton, silk, paper, wood, and polymers used in sculptures and photographies films as well as in other media. The aging properties of wool fibers and a comprehensive review of the aging, degradation, and conservation of historic materials made from cellulosic fibers will prove an invaluable resource for conservators of historic objects, art historians, academicians, and curators of museum collections who are responsible for the conservation and restoration of museum artifacts. This book examines the influence of mordants and natural dyes on the color fading and the degradation of cotton and silk fabrics and their implications for determining conditions for exhibition and display. Important analytical methods of high-performance size exclusion chromatography, viscometry, and gel electrophoresis are described as methods for assessing damage in silk tex tiles. The technique of microchemical manipulation, light microscopy, and FTIR ix In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. spectroscopy are described for the analysis of historic cotton fibers including those from a marine environment. Other spectroscopic investigations include the degradation of vulcanized natural rubber museum artifacts. Laser surface profilometry is introduced as a novel technique for the examination of polymer surfaces. Also included is a comparison of natural and artificial aging effects of cellulose acetate artifacts as followed by FTIR spectroscopy and ion chroma tography, and the applications of light microscopy and FTIR spectroscopy to distinguish between oil and acrylic painting media. This book will serve as a valuable tutorial and resource for the understanding of the properties of new and aged works of art across a broad spectrum of media. Aged historic objects present special problems and require unique solutions. Addressing the degradation of an aged object can require incor porating conventional and new technologies. The ACS is among the few publishers who offer basic and practical information on the application of science to the conservation of works of art. The time is ripe for such a pub lication to address the U.S. Government's Third Millennium Initiative that focuses on the preservation of historic objects. JEANETTE M. CARDAMONE Eastern Regional Research Center Agricultural Research Service U.S. Department of Agriculture 600 East Mermaid Lane Wyndmoor, PA 19038 MARY T. BAKER Chemonics International Egypt MVE 1133 20th Street, N.W. Washington, DC 20036 x In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. Chapter 1 Historic Textiles and Paper Jeanette M. Cardamone Eastern Regional Research Center, Agriculture Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038 The care of historic textiles and paper materials presents unique challenges for those working in conservation and restoration. The challenges are to maintain or reinforce the structural integrity and aesthetic appreciation of these objects while preserving authenticity through appropriate selection and application of materials and methods. The uniqueness of each object presents specific challenges for formulating decisions that not only require experience gained from similar pieces but also specific knowledge of materials and a firm understanding of the chemical and mechanical behaviors of all components of the object. Thus experience and knowledge become the underlying and fundamental basis for decisions regarding care. Historic textiles provide priceless records of the history of mankind. They are doubly significant because of their inherent documentary value and that of the objects produced from them. As depictions of the art and ethics of mankind with cultural, social, and political relevancy, historic textiles continue to inspire multidisciplinary studies. The marvel of textiles is in their construction from individual fibers that are assembled for processing through numerous steps and stages of yarn to fabric formation. Each fabric is a reflection of the aesthetic sense of the fabricator and the knowledge of how the sequence of processing steps such as scouring, bleaching, dyeing, and finishing can modify appearance. As one of the oldest skills, textile fabrication can provide a record of technological developments throughout the ages. Often the historic textile is composed of several different kinds of materials and some contain secondary materials, resulting from adding new to old, thereby conflicting the design and hand of the original maker. This complicated set of problems presents severe challenges for the conservator who restricts treatment to preserving the material and human evidence of the object. Alternatively, the restorer will strive to apply treatment 2 U.S. government work. Published 2001 American Chemical Society In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. 3 to return the textile to some semblance of its original appearance, structural integrity, and aesthetic quality. The predominant theme for the care of historic textiles is to preserve the authenticity of the object by appropriate care beginning with the selection of materials and methods of treatment. In the case of a textile of great historic significance that has survived in a fragmented state, decisions may be made to either replace the missing areas with sympathetic materials that are recognizably newer additions to enable the aesthetic appreciation of the piece, or to leave it in its original state. Fragmented textiles can be restored to the semblance of the original object by consolidating the remaining portions between transparent netting. For example, the author, as part of a restoration project at the Textile Conservation Centre, formerly at Hampton Court Palace, Surrey, England, partially restored an 18th century swallow-tail silk Guidon to its full size and shape with silk fabric of similar weight and construction that was dyed to the same shade as the original, before sandwiching it between silk crepeline that was dyed to the same color. When an historic textile is so severely degraded and friable that it cannot be exhibited, a decision may be made to consolidate it by casting a polymeric film to fill in missing areas in order to restore its original form. This method would be least desirable for it compromises a primary principle that restoration methods be reversible. Sometimes the historical significance of a piece extends to the deposited residues. The Shroud of Turin, thought to be the burial cloth of a crucified man (affirmed by some to be Jesus Christ), exhibits marks resembling blood residues that are positive renderings on a linen fabric bearing the photographically negative body image. The juxtaposition of these positive and negative images is of great importance for scholars who investigate the formation of the image for it suggests that the blood-like marks and body image were formed by different mechanisms. In another case, a heavily blood- encrusted military uniform might lose its fabric stability should it be subjected to cleaning before conservation or restoration. Woven tapestries present a unique challenge. In a "Great Tapestry" where there is an interlacing of highly twisted wool warp yarns with weft yarns of low twist, subjecting the fabric to wet cleaning will cause fiber swelling with differential yarn untwisting because the yarns will take up a greater surface area. Pockets and wrinkles will form throughout the fabric surface and they will act as light traps. The result is that the once youthful, mythological figures depicted in the tapestry will appear to be prematurely aged and this will diminish the aesthetic appeal of the piece. Thus, not only is it important to document the state of deterioration of a historic textile; but at the onset of investigation, it is extremely important to document thoroughly all textile components of the object and the object's past history. Complete understanding of all implications is critical for the appropriate care of a historic object. The fading characteristics of natural dyes, some mordanted with natural salts, is another consideration because they were used prevalently in historic tapestries. Generally, natural dyes exhibit poor light fastness. In some cases, the once green foliage and grass of old tapestries appear blue because of fading of the yellow dye component that was used in combination with blue to form the green color. The stability of color can be dependent on dye structure, the In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000. 4 presence of a mordanting salt, dyeing process, fiber type, quality and intensity of incident light, environmental exposure, relative humidity, and the ambient temperature. Natural fibers are proteinaceous (wool and silk) or cellulosic (cotton, paper, flax, hemp, and jute) in chemical composition. Within the classes of protein and cellulosic fibers there are not only differences in chemical reactivity but also differences in fiber morphology. When the fibers of these classes are compared, they exhibit diametrical chemical and mechanical properties. Different handling procedures and sets of conditions for treatments that are time-, temperature-, and concentration-dependent are required. Within certain time, temperature, and concentration ranges, protein and cellulosic fibers respond differently: wool fibers can be degraded by base and not by acid whereas cellulosic fibers can be degraded by acid but not by base. Chemical and morphological differences dictate how applied chemical, physical and mechanical forces will affect a historic textile. According to morphology differences, wool's mechanical profile is "soft" and extensible (due to a molecular coil configuration), whereas silk's profile is less pliable because its molecules are laid down in sheet-like form. Thus wool is more resilient and less prone to wrinkling. Mechanically, the cellulosics are relatively hard and brittle with little resiliency. They tend to deform permanently under mechanical stress so that wrinkles are retained. These factors influence every aspect of care including accession, documentation, conservation, restoration, exhibition, display, and storage. The degradation of wool is addressed in a chapter by Weatherall who postulates a mechanism for chemical changes resulting from light exposure that will aid in understanding the degraded state of a woolen artifact. In another chapter, Cardamone describes the fiber morphologies and characteristics of cotton and flax fibers and their modes of degradation. These chapters reinforce that the useful lifetime as a viable historic textile is limited by the stability of the basic chemical and morphological structure even though the textile object exhibits a somewhat stable fabric construction. Chen and Jakes describe the aging properties of marine cottons by documenting changes in crystallinity indices using FTIR microspectroscopy and microchemical reactions for analyzing chemical and physical changes and internal structural differences in dyed and undyed marine cottons after treatments with swelling agents. The degradation and color fading of prototype cotton fabrics dyed with natural dyes associated with metal salts were examined by Kohara, et al, and of prototype silk fabrics by Yatagai, et al. The authors describe the changes in mechanical properties and the influence of natural dyes and mordants on the aging of cotton and silk as monitored by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and electron spin resonance (ESR). A study by Tse describes the differences among three analytical methods; high performance size exclusion chromatography (HPSEC), viscosity, and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS- PAGE) for evaluating the degradation of silk after artificial light aging. The topical effects of aging are evident as discoloration that is In Historic Textiles, Papers, and Polymers in Museums; Cardamone, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2000.