Oil paintings in Southeast Asia present interesting conservation questions. This article identifies the materials and techniques of early 20th century oil paintings from institutions in Malaysia, the Philippines, Singapore and Thailand and their related condition in view of the elevated temperatures and relative humidity. It considers problematic materials and mechanisms known to paintings conservation in tropical climates and assesses them in terms of canvas painting practice identified in four institutions. Methods of investigation include technical examination and Electronic Speckle Pattern Interferometry to illustrate in plane dimensional movement. ESPI proved to be a useful diagnostic tool for in situ analysis of paintings on stretched canvas.