Debitus grisailles for stained-glass conservation: an analytical study

Abstract

 Article / Artigo II Colóquio Investigações em Conservação do Património II Colloquium Investigations in Heritage ConservationAs grisalhas Debitus para conservação de vitral: um estudo analítico Resumo A grisalha é uma das pinturas vítreas mais antigas e mais usadas na produção de painéis de vitral, e Debitus é uma das marcas comerciais mais conhecidas. As suas grisalhas são frequentemente utilizadas para reintegração cromática em restauro de vitral. Este artigo apresenta a análise química, morfológica e térmica de cinco grisalhas da Debitus, avaliando as suas propriedades antes e depois da cozedura com o objetivo de compreender a sua futura estabilidade. A caracterização foi realizada por microscopia ótica, microscopia eletrónica de varrimento, emissão de raios X induzida por partículas, difração de raios X e termografia de infravermelho. Este estudo demonstrou uma relação equilibrada entre os diferentes componentes e uma boa interdifusão no vidro por parte destes, tal como um comportamento térmico consistente entre eles e com o vidro, o que indica uma boa estabilidade e durabilidade destes materiais. AbstractGrisaille is one of the oldest and most widely used vitreous paint applied for the production of stained-glass panels and Debitus is one of the most renowned commercial brands whose grisailles are frequently used for the chromatic reintegration in stained-glass window restoration. This article presents the morphological, chemical and thermal analyses of five grisailles from Debitus, to evaluate their properties before and after firing with the objective of knowing their future stability. The characterisation was carried out by optical microscopy, scanning electron microscopy, particle induced X-ray emission, X-ray diffraction, and infrared thermography. This study showed a wellbalanced ratio between the different components and a good interdiffusion into the glass, as well as a consistent thermal behaviour between them and with the glass, which indicates the good stability and durability of these materials.

Impact of solar radiation and environmental temperature on Art Nouveau glass windows

“…The grisailles are made by powdering a highly fusible glass, usually lead glass, with pigments such as iron or copper oxides, but it can also contain tin, and/or manganese oxides. During firing, the grains of fusible glass melt and fix the pigment grains onto the glass surface [52][53][54][55]. On the other hand, an enamel is a brightly colored paint formed by a highly fusible glass, a lead glass with/without borax, with a small amount of pigment.…”

Grisailles: Reconstruction and characterization of historical recipes

“…), followed by slow cooling to room temperature, following the protocol used to fire Debitus commercial grisailles. Currently, they are the most used grisailles in the conservation and restoration of stained‐glass, having a composition based on historical grisailles 28 . The same firing temperature was used for all samples to allow a systematic study.…”

Comparison of four mobile, non‐invasive diagnostic techniques for differentiating glass types in historical leaded windows: MA‐XRF, UV–Vis–NIR, Raman spectroscopy and IRT

“…Infrared thermography has been used for a variety of art inspection and conservation cases, [ 24,25 ] including a few applications on glass materials, mostly stained‐glass windows. [ 26–30 ] The technique has proven effective in mapping the surface alteration features of archaeological glass, [ 26 ] and in distinguishing for example, soda‐lime base glass and applied lead‐glass paint in stained glass windows due to differences in heat accumulation. [ 30 ]…”