EnViCET: Glass disease: causes, effects and treatments

Teresa Palomar Sanz holds a PhD in Chemistry from the Autonomous University of Madrid and a master’s degree in Conservation Science (Pablo de Olavide University). She has developed her research career at the Instituto de Historia, the Centro Nacional de Investigaciones Metalúrgicas (National Metallurgical Research Centre) and the Instituto de Cerámica y Vidrio (Institute of Ceramics and Glass) of the Consejo Superior de Investigaciones Científicas (Higher Council of Scientific Research) focusing mainly on the conservation of inorganic materials of cultural heritage, especially glass and metal. She has also completed a post-doctoral stay at the VICARTE research unit “Glass and Ceramics for the Arts” (Portugal). She was the manager of the Observatory for Research in Conservation of Cultural Heritage until December 2015 and professor of the Scientific Department of the School of Glass of the National Glass Centre Foundation (San Ildefonso, Segovia). Since September 2018 and until 2021, she was a ComFuturo researcher in the Institute of Ceramics and Glass where she carried out her ComFuturo project “Glass disease: causes, effects and treatments“.

Project Summary

Some of the most sumptuous pieces of the 19th century manufactured by the Royal Glass Factory of La Granja have the pathology of crizzling. This is a serious conservation problem for historical glass with low chemical stability, since it is susceptible to alteration by ambient humidity and organic acids. There is no way to stabilise the alteration of these pieces without strict environmental control, which is difficult to implement due to the museum environment in which they are located.

Therefore, the objective of this project is to explore this pathology in greater depth, through a historical and environmental study of the affected pieces, the identification of the mechanism of alteration in affected model glasses with different chemical compositions, and the evaluation of the most common conservation treatments, as well as the development of new methods to stabilise the surface of the glasses affected by the crizzling. These results will serve to improve the conservation conditions of objects affected by this pathology, both in Spanish museums and in institutions in other countries.

Application: The aim of this project is to carry out a systematic approach to the pathology of crizzling through historical, archaeometric and environmental study of the affected pieces in the collections of the Royal Palace (Madrid) and the Museum of Glass Technology (San Ildefonso, Segovia), conducting systematic laboratory studies to find out the impact of moisture and formic acid on these glasses, and evaluating the most common conservation treatments.

Scientific output derived from the ComFuturo EnViCET project

Scientific articles  

R. Arevalo, M. Aparicio, J. Mosa, T. Palomar (2021) The stability of Ravenscroft Glass. Influence of composition and environment. JOURNAL OF NON-CRYSTALLINE SOLIDS. DOI: 10.1016/j.jnoncrysol.2021.120854


T. Palomar, N. García-Patrón, P. Pastor (2021) Spanish Royal glasses with crizzling in historical buildings. The importance of environmental monitoring for their conservation. BUILDING AND ENVIRONMENT. DOI: 10.1016/j.buildenv.2021.108054


R. Arévalo, J. Mosa, M. Aparicio, T. Palomar (2021) Different low-cost materials to prevent the alteration induced by formic acid on unstable glasses. HERITAGE SCIENCE. DOI:10.1186/s40494-021-00617-x


C. Machado; M. Vilarigues; T. Palomar (2021) Characterization of the Alteration of Debitus Grisailles. STUDIES IN CONSERVATION. En prensa. DOI:10.1080/00393630.2021.1890965


A. Gomez-Moron; T. Palomar; P. Ortiz; M. Vilarigues; L. Cerqueira; N. Schibille (2021) Christian-Muslim contacts across the Mediterranean: Byzantine glass mosaics in the Great Umayyad Mosque of Córdoba (Spain). JOURNAL OF ARCHAEOLOGICAL SCIENCE. DOI:10.1016/j.jas.2021.105370


C. Machado; M. Vilarigues; T. Palomar (2021) Historical grisailles characterisation: A literature review. JOURNAL OF CULTURAL HERITAGE. DOI:10.1016/j.culher.2021.03.010


M. Oujja, T. Palomar, M. Martínez-Weinbaum, S. Martínez-Ramírez, M. Castillejo (2021) Characterization of medieval-like glass alteration layers by laser spectroscopy and nonlinear optical microscopy. EUROPEAN PHYSICAL JOURNAL PLUS. DOI:10.1140/epjp/s13360-021-01834-w


C. Reis Santos; M. Vilarigues; P. Dabas; I. Coutinho; T. Palomar (2020) Reproducing crystal glass from three 18th-20th centuries Portuguese glass arcana. INTERNATIONAL JOURNAL OF APPLIED GLASS SCIENCE. DOI:10.1111/ijag.15611


T. Palomar; J. Mosa, M. Aparicio (2020). Hydrolytic resistance of K2O-PbO-SiO2 glasses. JOURNAL OF THE AMERICAN CERAMIC SOCIETY. DOI:10.1111/jace.17202


T. Palomar; A. Rodrigues (2020). Environmental degradation of Modern non-balanced glasses. GE-CONSERVATION. DOI:10.37558/gec.v17i1.690


C. Machado; A. Machado; T. Palomar; M. Vilarigues (2019) Grisaille in historical written sources. JOURNAL OF GLASS STUDIES. www.jstor.org/stable/26862829


C. Machado; A. Machado; T. Palomar; L. Cerqueira; M. Vilarigues (2019) Debitus grisailles for stained-glass conservation: an analytical study. CONSERVAR PATRIMONIO. DOI: 10.14568/cp2018067


T. Palomar, C. Grazia, I. Pombo Cardoso, M. Vilarigues, C. Miliani, A. Romani (2019) Analysis of chromophores in stained-glass windows using visible hyperspectral imaging in-situ. SPECTROCHIMICA ACTA PART A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY. DOI:10.1016/j.saa.2019.117378


T. Palomar; M. Silva; M. Vilarigues; I. Pombo Cardoso; D. Giovannacci (2019). Impact of solar radiation and environmental temperature on Art Nouveau glass windows. HERITAGE SCIENCE. DOI:10.1186/s40494-019-0325-3


Works presented at conferences

M. Martínez-Weinbaum; M. Sanz; F. Agua; D. Morales-Martin; S. Martínez-Ramírez; T. Palomar; M. García-Heras; M.A. Villegas; M. Castillejo; M. Oujja. Laser Induced Breakdown Spectroscopy and Nonlinear Optical Microscopy for Analysis of Historical Glasses. 11th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy (EMS-LIBS). Gijón, Spain. 29/11/2021-2/12/2021


C. Machado; M. Vilarigues; T. Palomar. Grisaille’s recipes: raw materials and their influence in the paint stability. 22nd Congress of the Association International pour l’Histoire du Verre & ICOM Glass Annual Meeting 2021. Lisboa, Portugal. 13/09/2021-17/09/2021


T. Palomar; P. Pastor; N. García-Patrón; M.A. Villegas; F. Agua; R. Arévalo; M. Álvarez de Buergo; R. Fort; M. Aparicio. La enfermedad del vidrio: causas, efectos y tratamientos. Congreso Ciencia y Arte VIII. Oral presentation. Madrid, Spain. 2/06/2021-4/06/2021


T. Palomar; P. Pastor; N. García-Patrón. Crizzling in Spanish Royal glasses, how to preserve them in historical buildings? Indoor Air Quality in Heritage and Historic Environments – IAQ 2020. Oral presentation. Amberes, Belgium. 12/10/2020-16/10/2020


R. Areval;, J. Mosa; M. Aparicio; T. Palomar. La estabilidad del vidrio de Ravenscroft. Influencia de la composición y el medio ambiente LVII Congreso Nacional de la Sociedad Española de Cerámica y Vidrio. Oral presentation. Castellón, Spain. 26/10/2020-29/10/2020


T. Palomar; M.A. Gómez- Morón. Mosaicos. Estudio de las teselas vítreas. Congreso Arq.Osio. Arqueología y arquitectura en el conjunto monumental mezquita-catedral. Del complejo episcopal a la Macsura. Invited oral presentation. Córdoba, Spain. 6/11/2019—8/11/2019


C. Machado; M. Vilarigues; L. Cerqueira; T. Palomar. European 20th century grisailles: comparing their characteristics. 5th Interim Meeting of ICOM-CC Glass and Ceramics. Poster. London, United Kingdom. 5/09/2019-7/09/2019


T. Palomar; D. Giovannacci; M. Silva; M. Vilarigues; I. Pombo Cardoso. Monitoring the natural heating of two Art Nouveau glass windows by IR-thermography. 5th Interim Meeting of ICOM-CC Glass and Ceramics. Oral presentation. London, United Kingdom. 5/09/2019-7/09/2019


C. Machado; M. Vilarigues; T. Palomar. Spotting the differences, a look into Grisaille and Black enamel recipes in historical written source. MATERIAIS 2019, XIX Congresso da Sociedade Portuguesa de Materiais and X International Symposium on Materials. Poster. Lisboa, Portugal. 14/04/2019-17/04/2019


C. Machado; M. Vilarigues; T. Palomar. Durability and stability study of Debitus grisailles. TechnoHeritage 2019. Oral presentation. Seville, Spain. 26/03/2019–30/03/2019


T. Palomar; M. Aparicio; P. Pastor; C. Mur de Viu; M. Alvarez de Buergo; E. Cano; M.A. Villegas. Glass disease: Causes, Effects, and Treatments (EnViCET project). TechnoHeritage 2019. Poster. Seville, Spain. 26/03/2019–30/03/2019


T. Palomar; M. Vilarigues; M. Silva; I. Pombo Cardoso; M.T. Marques; A. Mântua. Assessment of the conservation state and analysis of chromophores of two Art Nouveau glass windows. IPERION CH 3rd Transnational Access Users meeting. Oral presentation. Paris, France. 12/02/2019


A. Durán; Y. Castro; M.J. Pascual; F. Muñoz; M. Aparicio; J. Mosa; J.J. Velazquez; T. Palomar; L. Fernandez; G. Gorni; A. Triviño. Grupo GlaSS. Glasses, Glass-ceramics and Sol-gel materials for a Sustainable Society. Asamblea MATERPLAT 2018. Poster. Madrid, Spain. 14/11/2018


A. Durán; Y. Castro; M.J. Pascual; F. Muñoz; M. Aparicio; J. Mosa; J.J. Velazquez; T. Palomar; L. Fernandez; G. Gorni; A. Triviño. Grupo GlaSS. Glasses, Glass-ceramics and Sol-gel materials for a Sustainable Society. Industrial Networking at the V Spanish- Portuguese Congress of Ceramics and LVI National Conference of the Spanish Society of Ceramic and Glass. Poster. Barcelona, Spain. 8/10/2018–10/10/2018


C. Machado; A. Machado; T. Palomar; L.C. Alves; M. Vilarigues. Debitus grisailles for stained-glass conservation: an analytical study. 2nd colloquium on “Research on Heritage Conservation”. Oral presentation. Lisboa, Portugal. 28/09/2018–29/09/2018