Master – thesis abstracts 2013
Svenja Heidenreich. The „Kleiner Klebeband“ of the Fürsten zu Waldburg-Wolfegg. Concept for the preservation of old master drawings mounted in an album. In cooperation with the Kupferstichkabinett, Staatliche Museen zu Berlin, this project concerned the development of options for a preservation mounting solution for the collection of 15th- and 16th-century drawings assembled in the 17th century by Maximilian Willibald von Waldburg-Wolfegg and mounted in the 19th century in an album that does not fulfill current preservation requirements. Solutions for preserving the drawings in a mounted situation that is equivalent to their previous situation in the historic album are explored and model albums were constructed from which the most suitable system chosen by the interdisciplinary team was constructed to scale. It consists of variable designs of thin archival window mats each sewn separately into a book structure from which they can be individually removed by opening the front cover held to the book block by hidden earth magnets. The prototype will serve the decisions concerning the future preservation and access of the drawings and the album.
Catrin Schuster: Sodium borohydrideas a post-treatment after hydrogen peroxide bleaching. Hydrogen peroxide is a versatile oxidative bleaching agent that is used to diminish local or overall discoloration in paper. However, it poses the risk of damaging already aged cellulose. Sodium borohydride is not as versatile as other bleaching agents, however, it offers the advantage of reducing oxidized functional groups. The current project explores the consecutive use of the two bleaching agents where sodium borohydride is used as a reducing agent following the hydrogen peroxide bleaching treatment (3%, pH 9, 30 min) to counteract potential oxidative post-treatment effects that are damaging on the cellulose. The sodium borohydride applications included concentrations of 0.05, 0.2, 1, and 3%; it was applied by immersion for 30 min at all concentrations; the 1% solution was additionally applied by a 15 min immersion, and a 30 min aerosol application. Two naturally aged papers were treated and dynamically aged in sealed stacks exposed to temperature 6-hr temperature cycles (20–80ºC). Samples were analyzed for their average molecular weight, carbonyl group content and color. The effect of blistering (raking light, wrinkle meter) was also determined. The tests showed that an increase in the concentration range 0.05 to 1%, the sodium borohydride immersion after hydrogen peroxide bleaching diminished the molecular weight loss and the increase in carbonyl group content during artificial aging, as well as, to a slight extent, color reversion; increasing the immersion duration from 15 to 30 min also offered these benefits. The application of sodium borohydride as an aerosol had a distinctly negative effect, and the 3% immersion was less advantageous than those at lower concentrations for the stability of the aged samples. The major limiting factor of sodium borohydride immersion is blistering of the paper through formation of hydrogen gas bubbles, as observed on the short fibered samples. This made 0.2% sodium borohydride the highest concentration recommendable among those that were tested. The project was conducted in cooperation with the Department of Chemistry, at the University of Natural Resources and Life Sciences, Vienna. Publication: to be submitted.
Mareike Vay: Removal of an adhered book cover pasteboard from the front of a parchment illumination. The treatment problem focused on the removal of cardboard that was adhered to the surface of an illuminated parchment page belonging to the Universitätsbibliothek Graz. It had been re-used historically as a book cover for a publication dated 1586, and presumably bound close to that date. The parchment had been separated from the book cover at a previous date. Portions of the pasteboard were adhered with starch-based adhesive manuscript surface. Three treatment categories of increasing sensitivity of the original surface to moisture were identified: the plain parchment, from the manuscript areas, and removal from the painted areas. The cardboard was removed using a 10% methycellulose MH 30000 cast, sliced into small squares placed on the substrate to soften the adhesive locally. To avoid cockling and associated media loss during the treatment, the object was placed into a separate room in which the RH was raised gradually to 60% for treating the illuminated areas, and to 80% for the other areas; treatment was conducted in segments of two to three days max before the object was gradually returned to regular room climate at 50% RH over several hours. The introduction of moisture during treatment was additionally assisted by placing the object over a moistened blotter covered with a Gore-Tex® and blotters. Poulticing time was between 10 and 30 minutes, and close to the fragile media surfaces, a polyester fabric interleaving was used as a protective layer. Data loggers inserted into the support below the object and in the room monitored the RH. Humidification also assisted swelling the adhesive. The rate of moistening could be increased by increasing the room humidity, the poulticing duration, the amount of weight applied on top of it; excluding a Hollytex® interleaving layer between poultice and substrate. Flaking paint areas were consolidated prior to adhesive reduction using a brush application of a 1.5 % solution of sturgeon glue. Remnants of cardboard fibers and adhesive remain on the object. Parchment fragments were reattached and the page was inlay-mounted using Japanese paper strips. Paint particles irrecoverably loosened from the painting were analyzed with REM/EDX and identified to include red ochre, vermillion, azurite, copper-based green, lead white, chalk, gypsum, and body spar. The uncovered manuscript text was identified to be most likely a section of a commentary on the 12th-century Decretum Gratiani, written between the late 13th to 14th centuries. Publication: M. Vay, Andrea Pataki-Hundt, Freilegung einer Buchillumination. Ablösen einer verklebten Kartonschicht von einer illuminierten Makulatur-Pergamentbuchseite, Arbeitsblätter des Arbeitskreises Nordrhein-Westfälischer Papierrestauratoren e.V, Neuss, 2015: 55–60.
Nora Velensek: Large format – approach to storage and handling. Storage enclosure concept for oversized works on paper at the Kupferstichkabinett, Berlin. In cooperation with the Kupferstichkabinett, Staatliche Museen zu Berlin, this project concerned the development of options of enclosures for contemporary works of art on paper measuring between 600×420 mm and 1242×680 mm. These works require storage upgrade in the existing drawer flat file storage at the museum. A segment of up to 2000 objects in the collection was analyzed for sheet dimensions and aspect ratios, damage patterns and media sensitivities relating to storage and handling. The goal was to develop an enclosure system that would reduce the risk of mechanical damage and improve the ease of handling of the collection in the museum study room and for exhibition preparation. Therefore, the enclosures were to be designed compatible with frame dimensions also to be standardized in conjunction with the analysis of the artworks. Works were statistically grouped by dimensions and analyzed in relation to 9 frame formats, measuring between 845×640 mm and 1400×1000 mm, either already pre-established at the museum or suitable as new standard formats. The most common aspect ratio of 1407 objects analyzed was 1:1,4 followed by 1:1.3. These objects were grouped according to the most suitable identified frame formats, considering their visual compatibility. The most suitable enclosure, tested for handling in a medium-sized format 1130×860 mm, was established to consist of a shallow corrugated archival cardboard tray. A tray well holds several artworks, each enclosed either in a thin cardboard folder or in a folder featuring a thin corrugated backboard to be inserted in a frame by folding back its front cover. Stacks of these trays form a protective stack that is easily accessed. The stack perimeter forms an isolating barrier that retarded moisture transfer into the middle of a test stack during RH fluctuations cycling between ca. 75% and ca. 50% RH, 3 cycles 48 h each, constant T at 25°C. The final tray is to be pre-fabricated from single plotter-cut and folded corrugated board. Publication: N. Velensek, Fabienne Meyer, Eva Hummert, Irene Brückle. Stacked storage system for large works on paper. Restaurator, 35, 3-4 (2014): 287–314.
Lina Wällstedt: Effects of historical aqueous treatments recreated from recipes on the visual appearance of intaglio prints. In the condition evaluation of historical intaglio prints, the conservator today faces many cases in which prints underwent previous treatment. The study sorted out which types of largely mechanical manipulations involved in the historical interventions documented in the 17th and 20th-century restoration recipes and replicated selected treatment elements to study their effect on aged and modern intaglio prints. Samples underwent four different treatments: immersion in a saturated calcium hydroxide solution, repeated exposure to pouring hot water, immersion in a soap solution assisted by surface brushing, immersion in deionized water followed by brush-applied surface sizing with a 1% aqueous gelatin solution. The soap solution-immersed sample was pressed wet between blotters for drying, all other samples were air-dried. In addition, historical prints from the prints and drawings collection of the art history department at the Eberhard Karls Universität Tübingen were examined and documented for marks resulting either from print production, use, or treatment intervention: two 16th-engravings, available in 2 and 3 impressions, each respective set showing significantly differing material conditions; as well as two 19th-century etchings. The most useful methods of visual inspection were viewing under magnification and raking illumination at a low angle. The visual marks that determine the quality of printing were differentiated on modern samples and compared with historical prints: the influence of the paper quality, the condition of the printing plate, the manipulation of the printing ink during plate inking, the wear of the plate, the alteration of the print surface through abrasion and the mechanical impact of treatment. The most drastic loss of printing ink was caused as expected by the soap-washed, brushed and press-dried samples. The gelatin resizing intensified the darkness of the printing. The modern-prepared mock-ups of historical treatments supported the understanding of wear and treatment on the historical prints some of which had seen much intensive and diverse use, or had been lined and pressed.
Judith Becker. The account book of William Kilburn. Conservation of an album and preserving signs of historical use. BA-Thesis. Poster pdf: J. Becker, A. Pataki-Hundt, I. Brückle: Das Auftragsbuch von William Kilburn: Restaurierung eines Albums unter Erhaltung historischer Nutzungsspuren, 2015. Book publication: Gabriel Sempill and Simon Lawrence: Mr. Kilburn’s Calicos. The Fleece Press, Huddersfield 2014.
Maria Krämer. Separation of varnished cards of a Chinese domino game using cold temperature as treatment aid. BA-Thesis. Publication: M. Krämer, Eva Hummert, Irene Brückle. Die Trennung gefirnisster Karten eines chinesischen Dominospiels, Zeitschrift für Kunsttechnologie und Konservierung, 2016, in print. Poster pdf (same authors): Die Verpackung gefirnisster, permanent klebriger Spielkarten, Storage of varnished, permanently sticky playing cards, 2016.