This paper presents a technique to control the anisotropy of nickel-iron films by appropriate masking during deposition. Because of the demagnetizing effect, the resulting anisotropy is increased if ridges representing thickness variations are formed along the easy axis and is decreased if ridges are perpendicular to the easy axis. Low-anisotropy films may be applicable in thin film memories because of small driving fields and fast responses. A theoretical model is postulated to explain this effect. Some numerical calculations and experimental data confirm the predicted phenomenon.