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The International Paper Conservation Seminar has now been held as four face-to-face events and four online events. It is a three-day international event delivered in Spanish and Portugese with keynote talks from national and international conservation professionals from Mexico to Chile presenting projects covering works on paper in diverse formats including documents, photographs historic books, and artworks. Countries such as Argentina, Chile, Bolivia, Peru, Ecuador, Mexico, Paraguay, Uruguay, Colombia, Brazil, Spain and Costa Rica have sent delegates to discuss both the social and cultural aspects of conservation work. The seminar is a completely free event for its attendees. It is intended to be suitable for all, with high-level talks addressing issues of management, preservation, conservation, restoration and disaster recovery among many others. From the third event onwards, training workshops for basic treatments have been developed, with the participation of recognized conservation professionals from universities and international institutes, allowing the number of attendees to remain constant since the Covid-19 pandemic. It creates networks and fosters collaboration for professional and institutional projects. The seminars have generated a connected and active community of paper conservators in the region, aware of our limitations, and capable of solving problems collaboratively and according to local resources. [ABSTRACT FROM AUTHOR]

Calcium hydroxide nanoparticles dispersed in ethanol or 2-propanol have been proposed for deacidification treatments of cellulose-based supports and are currently adopted by many paper and paintings conservators. There is however a risk inherent in this treatment: the dispersion would acquire a highly alkaline pH in the presence of moisture, absorbed by the dispersing alcohol solvents or by the cellulose-based support. Consequently, conditions of potential risk would be created for the structural integrity of the cellulosic supports, for some organic film-forming materials and some colouring matter. The simple tests conducted in this study clearly demonstrate that this risk is real, and suggest a cautious attitude in evaluating the suitability of these nano-dispersions for the treatment of some works of art. [ABSTRACT FROM AUTHOR]

This paper presents the results of a series of tests – using a recently-published set of methodological guidelines referred to here as the Protocol – on varnishes traditionally used in the protection and enhancement of graphic artworks. The aim of the research was to study the characteristics of different varnishes when they are applied to a graphic artwork and to analyze their behavior when exposed to conditions that cause alterations, be these natural factors, accidental, or the result of a conservation intervention. Lastly, the study sought to determine whether each varnish was suitable for conservation purposes. Five varnishes were selected for the study: egg white, gum arabic, shellac, rosin, and dammar. Paper test samples were used to study the characteristics of the recently applied varnishes: dimensions, weight, thickness, color, brightness/gloss, pH, surface appearance, drying time, degree of absorption by the substrate, and adhesion to the substrate. The behavior of varnishes was studied via a series of tests that recreated adverse conditions (humidity, light, and temperature). These tested for resistance to ambient humidity, immersion in water, dry-heat aging, and aging in a climate test chamber. After applying the Protocol it was concluded that the varnishes most resistant to different alteration factors are gum arabic and dammar resin. By contrast, shellac and rosin are the most susceptible to alterations, which precludes their use as a conservation material. As well as indicating the varnishes that present the minimum interaction with the substrate and the greatest long-term durability, the results of this research also provide a useful guide to the behavior of these varnishes for their use in preventive conservation. [ABSTRACT FROM AUTHOR]

A small box, hitherto described as white lacquerware, currently displayed at the Chinese Pavilion, Drottningholm, Sweden, is an unusual example of artefacts imported from the Far East during the era of the East India Companies. By using microscopy for cross- and thin sections, X−ray fluorescence microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography-mass spectrometry, some of the specific characteristics of the box are described, and it was possible to differentiate original from more recent restoration material. Among other findings, the results suggest that white glue tempera is a better description, based on indications of calcium carbonate and protein, and support an earlier attribution of the box to an Edo period doll maker in Kyoto. [ABSTRACT FROM AUTHOR]

To study the life expectancy and difference in aging resistance properties of different modern repair bamboo papers, hydrothermal/dry-heat ageing experiments on repair bamboo paper samples were conducted. The mechanical strength (tensile strength and folding endurance) of different papers during the ageing process were analyzed. Furthermore, the chemical properties (degree of polymerization and pH) of the samples were tested to search for the immanent cause of paper ageing. The results indicated that the ageing resistance ability and durability of modern repair paper are strongly related to their production process, which corresponds with the initial properties of the paper. Mechanical pulp had a low degradation resistance, which was further exacerbated by the chemical bleaching process. In the long run, traditional handmade papers with solar bleaching processes will have longer-term stability and durability. [ABSTRACT FROM AUTHOR]

Despite substantial literature on the dyeing of textiles, there is a lack of research about colouring Japanese mending papers (tissue papers) used for paper conservation purposes. This study investigates the fungal bioreceptivity of Japanese tissue papers after they have been treated with various dyes and pigments. A variety of toning materials including plant dyes, watercolours, acrylic paints, inks, pastels, gouaches, and colour pencils are commonly used by conservators for paper toning purposes. In this study, two Japanese tissue papers (Yukyu-shiandSekishu Mare) were treated with selected plant dyes, watercolours, and acrylic paints and then inoculated with fungal species. Quantitative real-time polymerase chain reaction (qPCR) was used to quantify the DNA fromAspergillus nigerandPenicillium rubrumas a proxy for fungal species abundance before and after inoculation and artificial moist heat ageing. qPCR primers which were universal for fungi amplified DNA from papers inoculated withA. nigerandP. rubrumand these species were found to grow less on treatedSekishu MareandYukyu-shipapers compared with untreated papers.Sekishu Marepapers treated with artists' acrylic paints were found to be more resistant to fungal growth than similarly treatedYukyu-shipapers. This study suggests that for the best long-term preservation outcomes for paper materials in archives, libraries, galleries, and museums, acrylic paints generally perform better in conservation terms than most plant dyes and watercolours, although most colourants displayed some bioinhibition. [ABSTRACT FROM PUBLISHER]

When dealing with contemporary art, conservators have to address not only the material aspects of the artwork but also other highly complex issues. The Argentinian artist Leon Ferrari is a representative example. He created avant-garde art installations but also worked with traditional techniques. His works raise dilemmas over concepts such as authorship, authenticity, legitimacy of art. Some of his artworks only interested him as a means to express his opinions and he was not concerned about alterations in their appearance. Therefore, what should be kept in them is not in an area of certainty for conservators. An essential key for achieving a responsible and respectful conservation result, is to understand the ideology involved in each ‘art piece’ created by Ferrari. [ABSTRACT FROM AUTHOR]

A 2014 exhibition of Meriç Algün Ringborg at Moderna Museet, Stockholm, Sweden, exploring identity and belonging involved the making of facsimiles. The installation included a sound work, booklets to be taken, and a book to be read. Exhibition copies were created of personal letters for open display which were not to be touched. Contrary to the artist's wishes, the work was constantly handled. Made for this one installation, the facsimiles transcended the exhibition and were returned with the work to the artist. The paper examines issues of authenticity and control from a conservation standpoint, and details discussions surrounding reproduction in contemporary art museum conservation practice. [ABSTRACT FROM AUTHOR]

The implementation of chemical filtration in air-conditioning systems in archive and library repositories has become standard practice for heritage institutions in many countries. This practice is codified in official standards with general reference to a substantial body of scientific publications on the effects of air pollutants on paper materials. In this paper we report the application of a well-established decision analysis approach elaborating an integral cost-benefit perspective to provide decision support to four European national heritage institutions confronted with dilemmas in connection to chemical air filtration. Available scientific evidence for air pollution induced damage of paper material is reviewed and weighed against financial and environmental costs of air pollution control. Exposure of paper to both indoor and outdoor generated air pollutants at typical concentration levels observed within storage areas is expected to cause minimal to no additional yellowing and embrittlement, while the costs of chemical air filtration are significant. From a cost-benefit perspective the use of chemical air filtration in typical library and archive repositories is therefore discouraged. [ABSTRACT FROM PUBLISHER]

This study focuses on the changes in properties of cellulose-based paper, which can take place as a consequence of its contamination by dust particles. The PM1 (fine) and PM10 (coarse) fractions of the dust particles from archival repositories were collected on cellulose filters Whatman 41, polytetrafluorethylene, and quartz filters. The latter two types of samples were subsequently analyzed gravimetrically, with ion chromatography, PIXE, and the thermal–optical transmission method, giving mass, ionic, elemental carbon, and organic carbon concentrations. After artificial aging, the viscosity-average degree of polymerization of cellulose (DPv) was measured. It was confirmed that cellulose-based paper can undergo substantial changes when contaminated by dust particles and artificially aged. The decrease of the DPvof cellulose showed a negative correlation with the deposited mass of sulfate ions in the dust particles. Considering the particle size fraction, the results suggest the decisive importance of the fine (PM1) particles. The results provide better understanding of how particulate matter contributes to the chemical degradation of cellulose-based paper. Such knowledge is of importance when considering appropriate conservation measures in archives, libraries, and galleries. [ABSTRACT FROM AUTHOR]

The article presents an evaluation study for the matting and framing methods along with the materials used for the temporary display and preservation of photographs and other art works on paper. Topics discussed include the need to improve traditional in-house framing practices used for photographs, details of the design of experiment (DoE) used for the overall evaluation and the testing of the photographic frames in microclimate conditions. The article also includes the conclusion derived from the research.

A systematic experimental study applying nanosecond laser pulses with 532 nm radiation to a specially selected set of historical paper samples exhibiting a broad range of composition and origin was undertaken to develop a quantitative irradiation dose model. This allows the optimisation of laser pulse number and fluence in order to maximise cleaning efficiency while excluding substrate modifications such as yellowing or destruction. [ABSTRACT FROM AUTHOR]

There has been a growing interest in laser cleaning applications for a variety of organic materials such as paper, parchment, textiles, and leather during the last decade. However, archaeological organic materials, notably papyrus, have rarely been investigated. This contribution examines whether removal of burial encrustation can be justified in view of its short-term and long-term effects on the substrate. To examine this, tests using mock objects have been performed. Using artificially soiled and archaeological papyrus samples, optimization of laser cleaning parameters using a picosecond laser (1064 nm, various operating conditions) was attempted. Optimization was based on colorimetry, optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and cellulose degree of polymerization data, both before and after accelerated degradation. In papyrus, there is no clear damage threshold, and substrate degradation can always be observed and is comparable in treated (cleaned) and untreated (soiled) objects. Therefore, the decision on whether to clean papyrus using lasers is predominantly based on aesthetic and treatability (e.g. need for consolidation) criteria. [ABSTRACT FROM AUTHOR]

The article focuses on the use of design of experiment (DoE) approach for photographs and paper works which may get damaged by the environmental changes. It discusses the need for controlling the environmental factors like relative humidity (RH) and temperature, how the research information gathered have made it possible to recommend materials for framing of photographs and paper in museum collection. It also talks about the use of Mavelseal, which can help to reduce the humidity fluctuations with marginal costs.

The article looks at traditional Korean practices of the mounting of paintings, discussing a research project on the subject being carried out at Paris-Sorbonne University, Paris, France and the Hirayama Studio of the British Museum, London, England. It focuses on two 18th-century portrait paintings from the Joseon dynasty period, a portrait of scholar Kang Se-hwang and a portrait of Korean Prime Minister Ch'ae Che-gong, both attributed to artist Yi Myong-gi. Topics include the rarity of older Korean paintings with their original mountings, the use of silk backings, rods, and roller knobs in mountings, and differences between Korean, Japanese, and Chinese mountings.

A Japanese painting on paper, in the form of a horizontal scroll from the Stibbert Museum in Florence, is being treated at the ISCR Paper Conservation Laboratory. The scroll, entitled Bamo Dōi-zu represents 33 different types of horses. Although there is no author's seal, it has been attributed to the famous Japanese artist, Kanō Sansetsu (1589-1651). Before conservation treatment, the artefact underwent technical and scientific examination in order to identify its materials and determine its conservation condition. As sampling paint layers from paintings on paper is extremely invasive, non-destructive techniques such as X-ray fluorescence spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and spectrophotometry were employed. Several points from the paper support were analysed: the metal-leaf decorations, the seals and calligraphy, as well as the painted horses. Results detected and revealed a very simple palette: cinnabar (or its synthetic equivalent vermillion), shell white, carbon black, and the organic yellow gamboge. Pure gold and silver leaves were used for decorating the frontispiece. Useful information was obtained from the paper support and on its conservation conditions. Micro-destructive analyses were also performed on a few paper fragments for microscopic and scanning electron microscope equipped with an X-ray probe analysis. Results showed that materials and techniques are consistent with the Kanō School period. [ABSTRACT FROM AUTHOR]

Historic parchment is a complex biological material, and due to various methods of production or inks used, unknown environmental histories of objects and heterogeneous nature of animal skin, it represents a particular analytical challenge. Due to the number of variables it is likely that patterns in degradation of these historic objects can only be revealed by surveying the material properties of a significant number of real objects. In this work, a sacrificial collection of ca. 100 historic parchments (fifteenth to twentieth century) was characterized using a range of techniques available to conservation practitioners that can usefully be used to reliably and rapidly characterize parchment. We focused on micro-destructive methods, such as shrinkage temperature ( Ts), as the most widely used indicator of parchment degradation. Lipid content, roughness, and ink pH were additionally measured, while a limited number of samples containing iron gall ink were also examined using scanning electron microscopy (SEM) and SEM-EDX, to explore the distribution of ink components. Even in the absence of detailed environmental histories, it is possible to acknowledge the significance of the effect of iron gall ink and its acidity, and of lipids on parchment degradation, as measured using Ts. This research reports valuable reference data, while the collection remains accessible for further research. [ABSTRACT FROM AUTHOR]

Upon aging, paper documents and books become progressively damaged. Paper deacidification is a fundamental conservation intervention. In this study, we report on the use of nanoparticles of titanium dioxide (TiO2) and magnesium hydroxide (Mg(OH)2) associated with hydroxyethylcellulose (HEC) to inhibit acidification, photo-induced degradation, and biodeterioration of paper. With the aid of ultrasound, Mg(OH)2 nanoparticles with a narrow size distribution can be obtained through homogeneous precipitation in water. Furthermore, to demonstrate the efficacy of the nanocomposite and the performance of treated and untreated paper, photo- and thermal-induced degradation is discussed. The results show that using the controlled double-jet precipitation (CDJP) it is possible to synthesize Mg(OH)2 particles with a narrow size distribution (18-87 nm). The nanocomposite of Mg(OH)2-TiO2-HEC increases the durability of paper by imparting fungal growth resistance (D= 34.6 mm), moderate alkalinity (pH = 8.4), mechanical reinforcement (from 817-896 N/m), and UV protection. Additionally, there is a slight color difference (ΔE* = 0.8) between the treated and untreated paper. Both photodegradation and thermal degradation indicate that the paper treated with this nanocomposite (Mg(OH)2-TiO-HEC) has increased stability. [ABSTRACT FROM AUTHOR]

Between 1941 and 1968, Marcel Duchamp produced a series of roughly 300 boxes, or Boîtes, containing, in his words, 'everything important that I have done' (Sargeant,W. 1952. Dada's Daddy: A New Tribute is Paid to Duchamp, Pioneer of Nonsense and Nihilism. Life, 32(17): 102). Over the course of 30 years and seven editions, Duchamp and his assistants filled these 'portable museums' with miniature reproductions of his most significant works. The materials used included leather, paper, cloth, metal, glass, ceramic, cellulose acetate, gouache, varnish, and wood. The variety of the constituent materials, and the complex physical and conceptual ways in which they interact, make conservation treatment of the Boîtes unusually challenging. The conservator must consider both the condition of the specific Boîte being treated and its relationship to the dozens of other Boîtes still in existence. After an overview of the history and manufacture of Duchamp's miniature museum, the results of a pilot survey of the condition of 19 Boîtes will be presented, and treatment solutions to the most common condition problems proposed. [ABSTRACT FROM AUTHOR]

Radiographic images of paper are used to study the watermarks and the pattern of chain and laid lines originating from the sieve used in the production of the paper. X-rays with low penetrative power are used to obtain images with sufficient contrast as a result of differences in thickness/density of the paper. This article explains the improvement in contrast which can he obtained by lowering the X-ray tube potential, which reduces the penetrative power of the beam. Lowering the tube potential is limited by the attenuation of the radiation in air, which ultimately becomes so strong that exposure times become Unacceptably long. By replacing the air with helium, this attenuation of the X-ray beam can be reduced. A container for helium was developed which had an airtight fit to the exit window of the X-ray tube and has an exit window of a very thin layer of polyethylene. The effect of the technique was investigated by measuring the first and second half value layer (HVL) the beam expressed in millimetres of high density polyethylene (HDPE). [ABSTRACT FROM AUTHOR]

The rusty-red, irregularly shaped areas known as foxing or fox spots are prevalent on rag paper used in books from the sixteenth to the nineteenth century. Foxing may vary in size from just visible spots to large areas covering most of a page, and in some cases the stain migrates through successive pages. The present study investigated the role of fungi in foxing, and the location and cause of the discoloration in these spots. Using light microscopy and staining with aqueous aniline blue, it was observed that the initial cause of the foxing was a group of separated conidia (spores) which had been deposited on the surface of the paper prior to printing and had germinated in situ during the slow drying of the paper. The colour in the foxed areas is due to an alkaline-soluble rusty-red material and an insoluble straw-coloured stain in the paper fibres. Observations of migrated stains support the theory that fox spots are part of three-dimensional stain structures which are generated in stacks of paper either during the manufacturing process or after binding. Papermakers' felts are suggested as the source of contamination, and autoxidation of lipids from the conidia is a possible cause of the discoloration of the fungal material and paper fibres. [ABSTRACT FROM AUTHOR]

Nitrogen dioxide is a common air pollutant, formed in the atmosphere from the nitric oxide emissions from fuel combustion sources. Samples of organic and inorganic pigments, iron inks on paper, and traditional Japanese textile dyes mordanted Onto silk were exposed to 0·50ppm NO2 in air for 12 weeks. Ten of the traditional natural organic colorant samples on paper tested showed measurable color changes (ΔE > 2) as a result of the NO2 exposure, as did several of the anthraquinone-based synthetic organic pigments. The arsenic sulfide pigments orpiment and realgar and the iron inks tested showed considerable color changes (ΔE > 5) over the 12-week period. Nine of the 23 Japanese dyed silk cloths changed color by at least two ΔE units, including an enju sample (derived from the Japanese pagoda tree) that faded by more than seven ΔE units An NO2 dose (concentration times duration of exposure) of the magnitude employed in this experiment would be experienced inside an unprotected museum in downtown Los Angeles over about a two-year period, and in many other cities within a period of five to six years. [ABSTRACT FROM AUTHOR]

The colorfastness of several traditional Japanese colorants upon exposure to atmospheric ozone was tested in a chamber exposure experiment. Samples, in the form of colorants applied to paper, dyes on silk cloth, and colorants on a nineteenth- century Japanese woodblock print, were exposed to an atmosphere containing 0·40 parts per million ozone at 22°C and 50% RH, in the absence of light, for 12 weeks. Color differences, calculated from the measured diffuse reflectance spectra, were used to assess the rate and extent of the ozone fading. Of the colorants applied to paper, orpiment was the only inorganic pigment that showed severe color loss after ozone exposure. Several organic colorants on paper also reacted, including the widely used plant colorants ai (indigo) and ukon (turmeric). The woodblock print, produced using the plant-derived colorants beni (safflower), ai (indigo), shiō (gamboge) and aigami (dayflower), showed significant ozone fading only in the blue and green areas, which contain ai. Several of the dyed silk cloths also exhibited some color change in this experiment, suggesting that prolonged exposure to atmospheric ozone could pose a risk to these materials as well. [ABSTRACT FROM AUTHOR]

The long-term effect of gamma irradiation on paper was studied. Three types of paper (pure rag, mixed rag and mechanically prepared woodpulp) were subjected to three treatments: gamma irradiation, accelerated dry aging, and radiation followed by aging. The effects of these treatments on the physical properties of the paper samples were assessed by measuring alterations in mechanical strength as determined by changes in folding endurance and tear resistance when compared to the untreated control samples. It was found that gamma irradiation caused a decrease in the mechanical strength of the papers similar to that resulting from accelerated dry aging. A synergistic effect was found when both irradiation and accelerated aging were performed on the paper samples, demonstrated by an even greater decrease in both fold endurance and tear resistance than that resulting from either gamma irradiation or accelerated dry aging alone. [ABSTRACT FROM AUTHOR]

Framed and glazed prints have been found to yellow rapidly when on exhibition. It was found that the frames all contained the fungicide thymol. Experimental work has shown that the discoloration is caused by photoxidation. The discoloration was present in the paper and in the polymethyl methacrylate glazing. Mass spectroscopy has revealed the presence of a polymer of thymol; there was no evidence for the expected oxidation products. [ABSTRACT FROM AUTHOR]

The article discusses the artificial aging of paper used in the conservation of historic paper documents, focusing on the durability such treated paper. Topics include a discussion of the pigments used, such as gamboge, ochre, and carbon black ink, and plant dyes used such as valonia, tea, sophora flower bud and Cape jasmine; the practice of thermal aging and ultraviolet light ageing; the suitability of various types of commercially available paint in China for restoration work; and assessments of the tensile, fold, and tear strength of xuan paper treated with such methods.