Various properties of polyvinylbutyral (PVB), the most widely used polymer binder in photothermographic imaging materials, have been identified and characterized. These properties, including its solution and coating behavior, its ability to disperse silver behenate, as well as being a reducing agent for it, and its compatibility with behenic acid can all be credited for its widespread use as a binder for photothermographic recording materials. The reducing character of PVB is particularly important, although it was not found to be a property common to all sources of PVB, and is strongly dependent upon manufacturing method and purity. It is concluded that it is the combination of reducing character of PVB, together with its strong affinity for behenic acid, plasticizing the matrix, that makes PVB the binder of choice for photothermographic recording materials. This model enables targeted screening of alternative polymers to be carried out for future generations of photothermographic recording materials.