Abstract: Process for forming images by heating, imagewise, to a temperature above a softening temperature, but below the thermal decomposition temperature, a solid layer of a mixture of a thermoplastic, amorphous, organic polymer and a liquid plasticizer therefor, the mixture being capable of existing in a metastable state and a stable state for a period sufficient to convert the stable polymer to the metastable state, heating the entire surface of the layer to a temperature between the softening temperature of the stable and metastable states, and converting the softened exposed image areas to a visible image by applying finely divided colored particles to the layer and removing them from nonexposed areas or by thermal transfer. The simple procedure is a dry process, and images of high quality and stability are obtained rapidly.