An injection moulding method for producing a moulded article; comprising: (i) providing a first mould component having a first mould component moulding surface and a first mould component engagement surface which meets the first mould component moulding surface at first mould component moulding edge, and a second mould component having a second mould component moulding surface and a second mould component engagement surface which meets the second mould component moulding surface at a second mould component moulding edge, the second mould component further including a movable core; (ii) securing a layer of film to the first mould component moulding surface; (iii) adjusting relative position of the first mould component and a second mould component to a closed position to define a mould cavity and in which the first mould component engagement surface is engaged with the second mould component engagement surface along a parting line, wherein in the closed position, the first mould component moulding edge is spaced from the second mould component moulding edge by an offset along the parting line; (iv) injecting molten moulding material into the mould cavity to enable the molten moulding material to contact the layer of film; (v) moving the movable core to compress the molten moulding material in the mould cavity; and (vi) cooling the compressed molten moulding material to bond the layer of film to the cooled moulding material to form the moulded article; wherein the second mould component includes an optical waveguide cavity having a cavity wall which forms part of the second mould component moulding surface, the cavity wall being arranged to meet the second mould component engagement surface at the second mould component edge. (i) providing a first mould component having a first mould component moulding surface and a first mould component engagement surface which meets the first mould component moulding surface at first mould component moulding edge, and a second mould component having a second mould component moulding surface and a second mould component engagement surface which meets the second mould component moulding surface at a second mould component moulding edge, the second mould component further including a movable core; (ii) securing a layer of film to the first mould component moulding surface; (iii) adjusting relative position of the first mould component and a second mould component to a closed position to define a mould cavity and in which the first mould component engagement surface is engaged with the second mould component engagement surface along a parting line, wherein in the closed position, the first mould component moulding edge is spaced from the second mould component moulding edge by an offset along the parting line; (iv) injecting molten moulding material into the mould cavity to enable the molten moulding material to contact the layer of film; (v) moving the movable core to compress the molten moulding material in the mould cavity; and (vi) cooling the compressed molten moulding material to bond the layer of film to the cooled moulding material to form the moulded article; wherein the second mould component includes an optical waveguide cavity having a cavity wall which forms part of the second mould component moulding surface, the cavity wall being arranged to meet the second mould component engagement surface at the second mould component edge.