Ancient binding media, varnishes and adhesives

This was first published as a textbook for conservation training courses at the Institut Royal du Patrimoine Artistique, Brussels, Belgium under the title of "Liants, vernis et adhésifs anciens". The liquid plastic materials used as binding media, varnishes, and adhesives are capable of forming a solid skin called a film when applied in a thin layer on substrates. The first part of the text presents a study of the physical and chemical properties of these film-forming materials in their liquid state, i.e., as solutions, dispersions, or emulsions, under the following subheadings: surface phenomena and wetting; stabilization of pigments; rheological properties; oil index and critical concentration.

At the solid stage are studied the formation of film by physical or chemical processes and the optical and mechanical properties of these films. In a second part, the main natural film-forming materials, regrouped in five categories derived from the animal, vegetable, and mineral kingdoms (lipids, glucides, proteids; terpenes or resinous materials; and empyreumatic materials such as tars and bitumens) are studied in further detail as to composition and properties.