A wind turbine blade having a longitudinal direction between a root end and a tip end, - wherein the wind turbine blade comprises at least a wind turbine blade component made of fibrous composite material and comprising a first type of reinforcement fibres having a first elastic modulus, and a second type of reinforcement fibres and a second elastic modulus, - wherein the wind turbine blade component comprises a thickness between a first surface and a second surface , - wherein the proportion between the first type of reinforcement fibres and the second type of reinforcement fibres gradually changes in a first direction of the wind turbine blade so that the elastic modulus gradually changes in said first direction, - wherein said gradual change in the first direction is provided by: - a first thickness section, where the first type of reinforcement fibres along a first common boundary between the first type of reinforcement fibres and the second type of reinforcement fibres are tapered towards the first surface of the wind turbine blade component in the first direction, and the second type of reinforcement fibres are tapered towards the second surface of the wind turbine blade component in a direction opposite the first direction, and - a second thickness section, where the first type of reinforcement fibres along a second common boundary between the first type of reinforcement fibres and the second type of reinforcement fibres are tapered towards the second surface of the wind turbine component in the first direction, and the second type of reinforcement fibres are tapered towards the first surface of the wind turbine component in a direction opposite the first direction, and - wherein the first type of fibres and the second type of fibres are two types of reinforcement fibres and J Z are embedded in a common polymer matrix. - wherein the wind turbine blade comprises at least a wind turbine blade component made of fibrous composite material and comprising a first type of reinforcement fibres having a first elastic modulus, and a second type of reinforcement fibres and a second elastic modulus, - wherein the wind turbine blade component comprises a thickness between a first surface and a second surface , - wherein the proportion between the first type of reinforcement fibres and the second type of reinforcement fibres gradually changes in a first direction of the wind turbine blade so that the elastic modulus gradually changes in said first direction, - wherein said gradual change in the first direction is provided by: - a first thickness section, where the first type of reinforcement fibres along a first common boundary between the first type of reinforcement fibres and the second type of reinforcement fibres are tapered towards the first surface of the wind turbine blade component in the first direction, and the second type of reinforcement fibres are tapered towards the second surface of the wind turbine blade component in a direction opposite the first direction, and - a second thickness section, where the first type of reinforcement fibres along a second common boundary between the first type of reinforcement fibres and the second type of reinforcement fibres are tapered towards the second surface of the wind turbine component in the first direction, and the second type of reinforcement fibres are tapered towards the first surface of the wind turbine component in a direction opposite the first direction, and - wherein the first type of fibres and the second type of fibres are two types of reinforcement fibres and J Z are embedded in a common polymer matrix. <EOS>