Abstract: The invention relates to composite materials of construction comprising thermosetting resins and fibrous reinforcing or filling agents therefore as well as methods for the fabrication thereof. The thermosetting resin composition comprises a particulate thermosetting phenol-aldehyde resin; and a particulate curing agent for the thermosetting resin. The curing agent is encapsulated in a water insoluble thermoplastic resin having a softening point higher than, (1) the melting point of said thermosetting resin and, (2) the temperature at which said thermosetting resin flows on a solid substrate. The encapsulating thermoplastic resin also is dissolvable in the thermosetting resin by heating said curing agent capable of curing said thermosetting resin upon melting of the encapsulating thermoplastic resin and release thereof.