Since 1970, canvas paintings as mechanical systems, and structural treatments for them have been studied more intensively than at any other time in the history of conservation. Still, many aspects of the behavior of canvas paintings as complex physical systems remain unknown, along with longterm effects of structural treatments and optimal systems for constructing new paintings. The aim of this paper is to clarify what is known and what is not known about these problems and to suggest areas for further research. The method used will be a historical survey of the literature on the subject, from works by A. P. Laurie, F. I. G. Rawlins, R. D. Buck. Sheldon Keck, and G. Urbani to more recent work by W. Percival-Prescott, M. Mecklenburg, V. Mehra, and G. Hedley.