Three surveys on the occurrence of foxing stains were carried out on papers dating from 1560 to 1975 in three Portuguese collections. Foxed papers were found to be more intensely and intrusively stained in certain time periods of each collection. Based on historical data and on the professional paper conservation experience, the authors linked the increased occurrence of foxing stains in certain time periods to the new papermaking processes and materials, which began to be introduced in the late 18th century, and in particular to a synergistic effect between three factors: the use of deficient gelatine sizing which began to present a poorer quality and homogeneity, the presence of iron-containing impurities throughout the paper leaf and a distinct sorbency of moisture. Observing batches of morphologically similar papers by using photographic imaging with different types of light sources and incidences, the authors verified that similar papers present similar foxing stains.

This work comprises the use of a multi-analytical approach combined with microbiological studies to characterize six paper samples, containing foxing stains, from the 20th century, regarding their cellulose matrix, fillers, and sizing materials, and to evaluate possible paper degradation that might have occurred during the foxing stains. Photography under different illuminations and optical microscopy were used for morphological characterization of the paper samples and foxing stains. Scanning electron microscopy coupled energy dispersive spectroscopy (SEM-EDS) was of particular importance for defining the presence of fiber disorder and disruption on the surface of some of the stains, and localized accumulations of mineral-like particles on the surface of others. SEM-EDS, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR), and energy dispersive X-ray fluorescence (EDXRF) were used for the identification of mineral fillers, whereas sizing agents were analyzed using ATR-FT-IR. EDXRF results showed that no differences, within the standard deviation, were found in iron and copper contents between the foxed and unfoxed areas. Fungi belonging to the genus Penicillium spp. were found in all the paper samples. Unfoxed areas presented lower contamination than the foxed areas.

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A group of eleven pastel portraits from the painter Jose Malhoa (1855-1933) is presented in this paper. Some years ago they were in excellent conservation condition although having been subjected to permanent exhibition for over 30 years in a non conditioned environment. Since then their mounting conditions suffered alterations and their conservation showed signs of degradation. The storage condition history and the evolution of the pastel degradation was carefully reconstructed as well as was identified the material constituents of the pastel portraits, their pigments, bindings and support materials. It was concluded that the glass encapsulation was the main reason for the welfare of the collection and that the type of mounting and housing is more important than the presence or not of moderate exposure to indoor light. No direct relationship was found between the paper composition and the alterations.

A method is presented for the treatment of pastels, which has been developed at the Instituto Portugues de Conservacao e Restauro (IPCR) since 1992. It consists of blotter washing in a humid environment (using ultrasonic humidification) and drying process under controlled conditions. Other conservation methods that are described in the conservation literature are used in an experimental work and a comparison is established. The results show that the IPCR procedure is the most advantageous because it combines the least alterations of the pictorial layer and a greater effectiveness and facility in the removal of the paper alteration products. It is also described the method used for conditioning the pastels in a controlled dry atmosphere before rehousing them in their original mountings, using glass encapsulation.

"A METHOD OF INVISIBLE CONSOLIDATION OF TEARS, TONING AND INFILLING TRANSPARENT PAPERS." Studies in Conservation, 47(sup2), p. 10