A window having with a first surface, a second surface and an edge face is provided. A mould having an upper section and a moulding bed with a mould surface, which together form a mould channel into which a polymeric material can be introduced to form the trim, is also provided. At least a part of the window is inserted into the mould channel so that the perimeter of first window surface contacts the moulding bed and the window surface extends parallel to the mould surface. The polymeric material is introduced into the mould channel and the polymeric material adheres to the perimeter of the second surface of the window to provide a trim section which projects beyond the second surface and covers the edge face of the window, while preventing the adhesion of the trim section to the edge face of the window.