the paper conservator journal of the c:rID United Kingdom Group paper group Volume 1 1976

Editor: Guy Petherbridge.

Published annually by the Paper Group, United Kingdom Group, International Institute for Conservation of Historic and Artistic Works. Executive Committee 1976/77: Paul Collet (Chairman), Denis Blunn, James Brockman, Sheila Fairbrass, Jane McAusland, Frederick Marsh, Bernard Middleton, Roger Powell, Phillip Stevens, Claire Waghorn (Honorary Secretary), Nigel Williams (Honorary Treasurer). Co-opted Members: David Baynes-Cope, Dr. Vincent Daniels, Michael Warnes.

© Paper Group 1976 ISSN 0309-4227

A MANUAL METHOD OF PAPER PULP APPLICATION IN THE CONSERVATION OF WORKS OF ART ON PAPER* Keiko Mizushima Keyes

The range of tools needed for the conservation process described.

Paper conservators are aware that paper pulp can be used for the conservation treatment of certain damaged works of art on paper, but many seem to hesitate employing this method in their work because of uncertainties about details in its actual application or a belief that large and costly apparati such as leaf-casting devices are necessary. The author wishes to present here a simple, manual method of applying paper pulp to damages on works of art on paper.

In the treatment of works of art on paper, one is usually dealing with one single sheet of paper at a time. The variety of papers used for works of art is immense in texture, weight, tone and other physical qual ities. The size of papers also ranges enormously, from large contemporary graphics and drawings to fifteenth century Italian nielli smaller than a postage stamp. The media used are also highly varied and diverse, and many do not endure excess moisture in treatment. And since their value as art objects I ies in their visual effect, repairs must be inobtrusive and inoffensive to the eyes. Paper conservators are forever faced with the problem of find­ing a "matching piece of paper", which can often create compromises and delay.

The use of paper pulp in the restoration of works of art on paper is a method flexible enough to accommodate the physical diversity of papers and the many media used. It will produce satisfactory results in visual effect, without endangering the objects. Time is also an important concern to most conservators, and the paper pulp technique greatly reduces certain time-consuming aspects of conventional restoration procedures. It is the author's belief that the applications of this technique are only limited by her colleagues' resourcefulness and ingenu ity, and it is her hope that th is presentation wi II encourage further development and exchange.

Equipment Electric blender, blades dulled to prevent cutting of fibre; I ight table; tweezers; spoons; small beaker; sprayer;

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Application of the fibre mixture. Th is is done over a light table to distinguish the damaged areas clearly and to match opacity.

smoothing brush; blotting paper, cut to convenient size; supporting material - flexible translucent sheets wh ich will easily release wet fibre and without pronounced texture, e.g. polyester web, polyester mesh; small silk screen frame, or any other device capable of forming an even sheet from fibre mixture.

Source of fibre All-rag paper: Lighter stock, with neutral, off-wh ite tone. Darker stock with tone of antiquation (e.g. J. Barcham Green "Cockerell" 15, or dyeing with appropriate dyes such as procion dye 16.)

Ifthe situation calls for specific fibre (e.g. oriental paper, Indian paper), use fibre from similar king of paper.

See Part II for appropriate papermak ing pulp.

Preparation of Fibre Mixture from All-Rag Paper

Test paper for acidity and deacidify if necessary. Prepare I ighter stock and darker stock separately. Tear paper into smaller pieces (approximately 1 inch square for normal rag paper). Soak in water 1-2 hours, then boil for approximately Yo hour. Place paper pieces in blender, discarding the water in which it was boiled. Add fresh water (de-ionized water is recommended). 10 to 15 grams of paper in dry state to 1 litre of water will make a convenient standard mixture. The proportion can be easily adjusted by adding or draining water from the standard mixture according to use. Blend 20-30 seconds at medium speed and test for "knots". Blending is completed when knots cease to form. The fibre mixture can be stored under refrigeration, frozen, or kept at room temperature with an appropriate preservative such as thymol dissolved in methanol.

Method of Application of Fibre Mixture: General Instructions

All preliminary treatment should be finished. Soil and

A MANUAL METHOD OF PAPER PULP APPLICATION

encrustations around edges of damaged areas should be removed. Bevelling of edges can be minimized as the fibre mixture will conform to make an even surface with the body of the object. To obtain the tone most closely resembling that of the object to be repaired, combine lighter and darker fibre mixtures, form swatches from the mixture, dry them and compare tones to that of the object in its dry state. When the appropriate mixture is obtained for the tone, adjust the degree of dilution by adding or draining water from the fibre mixture: a more dilute mixture for repairing I ighter weight paper, a denser mixture for heavier weight paper. Addition of a small amount of methyl cellulose (approximately % fluid ounce of a 1.5% solution to 1 litre of fibre mixture) is recommended for more even dispersion and adhesion of the fibre.

Method of Application for Objects not Endangered by Moisture

Place supporting material on the light table, apply moisture and smooth on securely to the table surface with a smoothing brush. Place supporting material on the I ight table, apply moisture and smooth on securely to the table surface with a smoothing brush. Place the object image-side down on the supporting material, moisten to relax fibre, and smooth on to the supporting material, tak ing care that tears are aligned. The object should be kept moist throughout the application of the fibre mixture. Apply fibre mixture, matching the opacity of the fibre mixture infill with that of the body of the object. Start from damages in the centre of the object and work out­ward. Smaller damages are filled by placing fibre mixture with tweezers and spoons; larger damages are filled by pouring fibre mixture from the spout of the beaker. Correct any unevenness of fibre dispersion while moist by tapping the fibre with tweezer points or belly of spoon. Remove excess fibre from edges of the filled areas with tweezers. A thin layer of fibre should be left narrowly overlapping the edges of the damaged area. Blot out moisture by placing a small piece of supporting material directly in contact with the filled area. Place a piece of blotting paper over this and apply light pressure by finger or palm.

In this method fibres are applied in situ over loss, tears, thinning, etc. (This is not a true paper making process). The application of dilute paste along the edges of the damaged area is recommended prior to fibre appl ication to ensure strong adhesion.

If the area of damage is of considerable size and requires a large amount of fibre mixture, a moistened cotton twine can be used to surround the area to prevent over­flow of the fibre mixture to unwanted areas. If the texture of the paper calls for laid lines and chain marks, a similar surface effect can be created by a stamp i ng device fabricated for th is purpose and impressed on the filled fibre mixture while moist.

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Method of Application for Objects Endangered by Moisture

Form a sheet from the fibre mixture with any device at hand. A silk screen may be used for this purpose. Float silk screen on water surface with screen-side down. Insert supporting material cut to size of screen, and smooth on to screen surface. Pour fibre mixture over supporting material. Agitate mixture to disperse fibre evenly. Lift frame quickly from the water surface. Drain initial moisture. Place frame over blotting paper to remove more moisture, and remove supporting material with formed sheet from screen surface. Dry the sheet, size as required, and insert pieces to damaged areas using conventional method. Imitation laid lines can be applied, if necessary.

Finishing

The object is air-dried, and excess fibre is pared away. This operation can be minimized if removal of excess fibre is properly done at the time of fibre opplication. Size the repaired areas either locally or together with the body of the object, and dry under su itable pressure. Colour compensation can be minimized if the tone of fibre mixture is properly matched before the appl ication.

* This paper was first presented to the fourth annual meeting of the American Institute for Conservation of Historic and Artistic Works. at Dearborn, Michigan, 29 May-1 June 1976 and was published in the Preprints of that meeting.

Dans Ie domaine de la conservation des I ivres et des documents la recherche sur les methodes utilisees pour Ie rempl issage avec de la pate a papier et Ie developpement de ces methodes ont deja en grande partie ete presentes. En raison de la nature des livres et des documents, I'accent a generalement ete porte sur I'uniformite, la multiplicite et la facilite de traitement d'une quantite importante en une fois. A cet effet, des machines pour 'formation de feuille' (leaf-casting) et d'autres appareils a grande echelle ont ete mis au point. Par opposition en ce qui concerne Ie traitement des oeuvres d'art sur papier, les imperatifs sont plus speci­fiques. En general, on traite une seule feuille de papier a la fois. La variete de texture, de poids, de ton et d'autres caracteristiques physiques des papiers employes pour les oeuvres d'art est immense. Les dimensions des feuilles varient egalement beaucoup. Les moyens d'expression employes sont aussi tres varies et divers et nombre d'entre eux ne tolerent pas I'humidite excessive au cours du traitement. Cet article decrit une methode manuel Ie simple et pratique pour I'application de fibres de papier pour la restauration d'oeuvres d'art sur papier.