Provides an overview of developments in frames that provide controlled elastic tension and addresses the question of what level of tension is most suitable. Research is going forward at the restoration laboratory of the Province of Viterbo (Italy) in order to define objective measurements and criteria. Other institutions have also joined the project, and new lines of research will be followed beginning in 2005. The main part of the article focuses on a series of measurements that are compared to the experience of a group of conservator-restorers, aiming at defining the correct tension value for the paintings under study. Parameters for a correct tension value are formulated. One result was identification of a value defined as “Maximum Useful Tension.” Beyond this point, a painting’s resistance to deformation does not improve substantially.