Solvents are used for many purposes in the conservation field. The conservation professional standard recommends using solvents of the highest purity to enable reaction predictability and avoid possible harmful residues. Solubility parameters explain why solutions show different qualities, depending on the affinity between solvent and polymer. It is assumed that each solvent leaves the polymer in a certain molecular arrangement, with more or less inner equilibrium, leading to different mechanical properties that may reflect physical aging reactions. In a “good solution” the molecules are fully unfolded, and each functional group along the polymer chain is occupied by the corresponding functional group of a solvent. In a “poor solution” some parts of the polymer molecule remain entangled. These molecular arrangements persist through the drying process, even exceeding the no-flow point. They become an immanent part of the film. A dried film from a good solution appears smooth, with an even molecular chain interaction of the many different molecules, whereas a poor film appears inconsistent and porous, with a rough (matte) surface. In particular, the evaporation time of a solvent seems to influence the quality of the formed film. The faster a solvent leaves the freshly applied wet film, the sooner the molecules will lose their chain mobility. They are thus hindered from building an inner equilibrium of charges and free volume, which leaves a fragile film prone to physical aging reactions. To assess the effect of solvents on the film-building quality of polymers, a thermal analysis study was undertaken. The aim of this paper is to foster research in this very important and underestimated aspect of solvent use in conservation.