W. (Bill) Wei was a senior conservation scientist at the Cultural Heritage Agency of the Netherlands, Amsterdam, until his retirement in 2021, and is now an independent consultant. He has a BSE in mechanical engineering from Princeton University, New Jersey (1977), and a PhD in materials science from the University of Illinois Urbana-Champaign, Illinois, USA (1983). Before working in the field of cultural heritage, he spent nearly 20 years in industrial materials research and development, focusing on fracture mechanics, fatigue, and corrosion. Dr Wei has been conducting research and consulting on the effects of vibrations and mechanical stresses on the condition of fragile works of art for more than 25 years. He also conducts research on perception related to conservation treatments and object appearance, risks posed to objects by mechanical loads, and conservation ethics.