Spring mechanisms have been developed, since late 1970s, to provide some freedom of deformation to the wooden supports of paintings; however, no scientific method is up to now available for optimizing their design parameters. This article deals with theoretical and experimental work on the replica of an actual wooden support restored in a Florentine laboratory. A model is developed to describe its deformational behaviour after an auxiliary support has been applied by means of springs. The main outcome of such a research, still on-going, is a numerical model verified experimentally, enabling a restorer to choose the most appropriate mechanical parameters for springs in order to obtain the desired control of deformations and stresses produced by the expected environmental conditions.