A method of moulding a moulding material to form a moulded part of fibre-reinforced resin matrix composite material, the method comprising the steps of: i. providing a plurality of layers of sheet moulding compound, each layer comprising a plurality of ribbons randomly distributed across the plane of the respective layer and at least partly coated by a resin, each ribbon comprising a bundle of mutually aligned carbon fibres and being randomly oriented within the plane of the layer, in each layer of sheet moulding compound the ribbons are distributed to cover less than 100%, optionally from 90 to 99%, of the layer area, relative to the plane of the layer, wherein each layer of sheet moulding compound has been formed by scattering a plurality of the ribbons either (i) onto a surface which is then coated with a resin layer or (ii) onto a resin layer, in each case to form a layer of the plurality of ribbons which are randomly distributed across the plane of the resin layer with there being gaps between adjacent ribbons and wherein at least some of the ribbons mutually overlap, the gaps optionally defining at least 10% of the area of the resin layer, and impregnating the ribbons by the resin, the impregnation causing lateral movement of at least some of the plurality of ribbons in the plane of the resin layer to reduce ribbon overlap, and to reduce the area of the gaps; ii. assembling the plurality of layers as a stack; iii. locating the stack in a moulding area of a mould tool, the mould tool defining a peripheral edge of the moulding area, wherein the stack of layers is shaped and dimensioned to cover from 90 to 100% of the moulding area and a peripheral edge of the stack is located at or inwardly of the peripheral edge of the moulding area, the stack of layers defining a panel part; iv. applying a moulding pressure to an upper surface of the stack and causing the sheet moulding compound to flow and fill a mould cavity, defined by the moulding area, of the mould tool; and v. solidifying the resin to form a moulded part from the moulding material, wherein the moulded part includes a panel portion formed from the panel part. i. providing a plurality of layers of sheet moulding compound, each layer comprising a plurality of ribbons randomly distributed across the plane of the respective layer and at least partly coated by a resin, each ribbon comprising a bundle of mutually aligned carbon fibres and being randomly oriented within the plane of the layer, in each layer of sheet moulding compound the ribbons are distributed to cover less than 100%, optionally from 90 to 99%, of the layer area, relative to the plane of the layer, wherein each layer of sheet moulding compound has been formed by scattering a plurality of the ribbons either (i) onto a surface which is then coated with a resin layer or (ii) onto a resin layer, in each case to form a layer of the plurality of ribbons which are randomly distributed across the plane of the resin layer with there being gaps between adjacent ribbons and wherein at least some of the ribbons mutually overlap, the gaps optionally defining at least 10% of the area of the resin layer, and impregnating the ribbons by the resin, the impregnation causing lateral movement of at least some of the plurality of ribbons in the plane of the resin layer to reduce ribbon overlap, and to reduce the area of the gaps; ii. assembling the plurality of layers as a stack; iii. locating the stack in a moulding area of a mould tool, the mould tool defining a peripheral edge of the moulding area, wherein the stack of layers is shaped and dimensioned to cover from 90 to 100% of the moulding area and a peripheral edge of the stack is located at or inwardly of the peripheral edge of the moulding area, the stack of layers defining a panel part; iv. applying a moulding pressure to an upper surface of the stack and causing the sheet moulding compound to flow and fill a mould cavity, defined by the moulding area, of the mould tool; and v. solidifying the resin to form a moulded part from the moulding material, wherein the moulded part includes a panel portion formed from the panel part.