Long-term proven? Characteristics of the popular conservation heat-seal adhesive BEVA 371 and its modifications: A review

• BEVA 371 is a long-established heat-seal adhesive and classified as stable. • The formulation has changed several times and is not fully traceable. • The substitution of one component (tackifier) increased the activation temperature. • The adhesive quality varies significantly in function of bonded materials and bonding procedure. • Bonding characteristics are difficult to predict, as systematic long-term studies are lacking. Since its introduction in the early 1970s, BEVA® 371 has become the most common conservation heat-seal adhesive. It is established across various fields and widely used as a lining adhesive for canvas paintings. Its key advantages include flexibility, reversibility, and compatibility with different materials. However, changes in formulation due to unavailable components have led to altered properties, like a rise in its activation temperature, which is crucial for an artwork's safety. Moreover, a new product has just been released. This comprehensive review uniquely synthesizes decades of research, manufacturer information, and original findings, providing the first cohesive overview of BEVA 371′s complex product and formulation history, focusing on material and adhesive properties in its use as an adhesive for canvas bonding. In this, the adhesive's effectiveness highly depends on factors such as activation temperature, application method, and material interactions. As BEVA 371 remains crucial in conservation, precise knowledge of the adhesive's characteristics is essential for assessing past, present, and future BEVA 371 applications that we will encounter in works of art in conservation practice.