A new microencapsulation method, in which a paraffin medium and small sub-micron spheres were encapsulated by an amino resin has been established. These multinuclear microparticles were made by polymerization in emulsion and characterized by scanning electron microscopy and interfacial tension measurements. This process is based on several emulsion mixings following Torza and Mason's approach, in which we combined the characteristics of a coacervation with a conventional interfacial reaction and an in situ polymerization followed by a water in oil in water emulsion. The inner phase of the microcapsules consisted of a mixture of paraffin and microspheres of poly(vinyl) alcohol/hydrated salt crosslinked by methylene diisocyanate. The encapsulation mechanism is based on the liquid/solid-liquid separation of methoxylolmelamines and will be described in this study to explain the surface morphology. (c) 2007 Wiley Periodicals, Inc.