Abstract of the DisclosureCompositions, for example cosmetic compositions, comprising at least one organic polymer, such as a crosslinked organosoluble polymer, and a mixture of at least two solvents, one of which is volatile and incompatible with the polymer, and the other of which is nonvolatile and compatible with the polymer. These compositions make it possible to form on keratin materials a deposit whose volume increases over time, without the intervention of an external stimulus. These compositions can be, for example, mascaras, lipsticks or anti-wrinkIe formulas in the form of a cream or a foundation. The cosmetic treatment processes using these compositions.