Process and plant for packaging in the fluid state substances which are sticky or soft at room or handling temperature, wherein the substance (A) is cast in a mould (1) provided with holes and lined, by means of vacuum thermoforming, with a thin film of plastic material (4) which is non-sticky at the room temperature and compatible, in the fluid state, with the sticky or soft substance (stage I). The free-surface of this substance thus formed is cooled (stage II) and finally covered with a non-sticky material (25) which is then heat-sealed with the film (stage III). The sealed materials are finally cut in the region of the sealed joint (stage IV).
