| I found the article entitled Paper and Conservation, which begins on the next page, in a catalog from PAPER TECHNOLOGIES. They granted us permission to reprint it and we reprint it for your information. But first, here is what Mr. Waldrum says about paper. "When I started making graphics, i.e., etchings and linocuts, I had had a dream that inspired me to make aquatint etchings, but mainly I had in mind having items which were less expensive than my paintings had become. At that time I was relatively ignorant concerning paper.I had admired paper and used a lot of it as supports for paintings. I especially liked the linen papers I purchased from David Davis in New York City. The first twelve etchings Las sombras de los edificios religiosos de Nuevo Mexico Norte printed by Robert Blanchard at Custom Etching Studio were printed on papers made specifically for that project by Russell Hamilton at Cuervo Creative Papers. Over the last fifteen years of producing graphics, I'm not sure when it happened, but I have learned to treat paper with reverence. Sometimes, I see a paper and start thinking about how I can use it, but then I remember that the paper is to serve the piece and not the other way around. With that in mind, I always search for the paper that serves the piece." PAPER AND CONSERVATION .All of us, who have been privileged to be connected with the manufacture, sale, or use of paper, sooner or later develop a very special relationship towards paper - we fall in love with it. It is a very subtle development, not a head over heels kind of falling in love, but a steadily growing awareness of the beauty of a well-made sheet, whether handmade or machine made, and a sincere appreciation of its functional properties for a given application. Fine Art Paper, certainly, is one of the very few commodities offered in any marketplace, which can inspire exclamations of admiration, not only from the producer, i.e., the papermaker, who knows a good sheet when he sees it or touches it, but also from the people who work with it on a regular basis, such as artists, printmakers, bookbinders, and last, but not least, conservators. From its inception in China, nearly two millenniums ago, papermaking has been considered an art form and, for centuries, during its arduous journey via Japan and the Near East to Europe, the papermaking process has been jealously guarded by a succession of rulers, sultans, and kings. Even today, with high-speed production and electronically guided manufacturing systems, papermakers still consider their work as art and are highly secretive of the procedures and formulations they employ. Instead of the vegetable fibers used by the Oriental papermakers, the Europeans and, later on, the Americans employed mostly linen and cotton rags as a raw material for papermaking, and the remarkably high quality of paper used in books from the incunabula period, i.e., books printed during the 15th century, is accounted for by the relatively pure conditions under which most handmade paper was manufactured. With the advent of machine age in the early part of the last century, extracted and refined wood fiber pulp was used on an ever increasing scale. With the manufacture of machine made papers, alum was introduced in papermaking. Alum is used to hold the rosin sizing to the fibers and this, in turn, results in an acid condition. Up to a few years ago, practically all machine made papers were made with alum/rosin sizing. Today, it is generally acknowledged that the residual acidity resulting from the use of alum in the manufacture of paper is the chief cause of fiber deterioration and loss of strength. However, acidity in paper may also be introduced by migration from other materials and is one of the side effects of industrial atmosphere and air pollution. Acidity in paper, regardless of its source, destroys the cellulose fibers by accelerating a chemical reaction which ruptures the long chain of molecules. As this acid hydrolysis continues and molecular chains are broken, the paper becomes weaker and more brittle until its use is dangerously impaired. Obviously, the best protection for paper is to eliminate the introduction of acid in the manufacturing process and, in the early 1950's, synthetic sizings were developed which require no alum to deposit on the fibers. Most of the acid-free papers offered for conservation use are made from either cotton fiber or from refined wood pulp. Cotton pulp, which now is generally made from linters rather than actual rags, is almost pure cellulose to begin with and, therefore, requires less treatment. As a rule, the cotton fibers remain longer and stronger than the fibers obtained from refined wood pulp. Unrefined wood pulp contains lignin which acts as a binding agent between cells. When it is exposed to light, lignin turns a dark color and, therefore must be eliminated to make a high grade of paper. Extensive cooking, bleaching and refining remove the lignin and other impurities and the remainder is mostly cellulose. In paper conservation today, conservators insist on the use of acid-free and lignin-free papers and, in general, prefer the use of papers which are manufactured slightly on the alkaline side, with a pH between 7.5 and 8.5, filled with a small percentage of calcium carbonate or magnesium carbonate, which keeps the paper in an acid-free range. The buffering will help to combat acid deterioration caused by atmospheric conditions and/or by acid migration, i.e., by contact with acidic materials. However, the slightly alkaline environment created by the buffering of paper is not desirable for all conservation applications. In particular, it is not recommended for the preservation of certain types of photographs, such as albumen and color prints, and for the protection of protein-based materials in textile conservation, such as wool and silk. Special grades of acid-free papers which are unbuffered are supplied for the conservation of these materials. In paper conservation, a distinction is made between permanent papers and durable papers. In general, permanent papers are high-purity archival quality papers which exhibit a high degree of permanence in storage, i.e., papers which show maximum resistance to aging and, as a rule contain an alkaline reserve - they are buffered. Papers which have a high degree of initial strength, such as long fibered papers made from cotton, linen, or alpha cellulose, and which retain their strength while being handled frequently, are considered durable papers. To produce permanent and/or durable papers, the manufacturer has to pay special attention not only to the proper selection of the fiber, but also to the processing of the pulp, type of sizing, etc. | |
