Abstract: A first layer of photoresist material, sensitive to radiation of a first wavelength, has a second layer of photoresist material, sensitive to radiation of a second wavelength, deposited thereon. A pattern of radiation of the second wavelength is then formed on the second layer of photoresist material which is subsequently treated with a solvent, in which the first layer of photoresist material is insoluble, to develop a first periodic profile. The first layer of photoresist material is then exposed to radiation of the first wavelength through the first periodic profile and treated to develop a second periodic profile. By directing the radiation of the second wavelength through the first periodic profile at an angle to normal to the first material photoresist material a blaze profile may be obtained.