An aesthetically pleasing, slim profile window frame assembly that is capable of retaining a shutter. Specifically, the window frame assembly of the present invention comprises a core substrate coupled to a flange. Certain embodiments of the present invention comprise a core substrate having a thickness less than 5/16 inch and having, by volume, an elastic modulus greater than wood. A flange comprises a depth sufficient to retain a hinge attached to a window covering, such as a shutter. Certain embodiments of the present invention provide for a decorative covering to be coupled to the core substrate and/or flange such that a portion of the window frame assembly is thereby concealed. The improved strength per volume of the present invention facilitates shutter installation by a “do-it-yourself” homeowner or handyman as well as by a skilled carpenter.