A composite core material and methods for making same are disclosed herein. The composite core material comprises mineral filler discontinuous portions disposed in a continuous encapsulating resin. Further, the method for forming a composite core material comprises the steps of forming a mixture comprising mineral filler, an encapsulating prepolymer, and a polymerization catalyst; disposing the mixture onto a moving belt; and polymerizing said encapsulating prepolymer to form a composite core material comprising mineral filler discontinuous portions disposed in a continuous encapsulating resin.