A surface relief grating image machining process andor product. In cases where the polymer is cross-linking, the energy source assists in cross-linking of the polymer. In a preferred embodiment, the mooring system comprises two vertical arms connected to a triangular horizontal yoke attached to the bow of the LNG-carrier for improved yaw resistance. The behavior of the colored markers when an object touches the curved surface of the elastic body is obtained as image information of markers by photographing device.