Two-step spatially delineated growth of copper lines from a solid copper formate layer on a surface is demonstrated. In the first step, a localized platinum film, less than 10 .ANG. high, is deposited. Subsequently the whole surface is covered by a few microns of Cu(HCOO)2.2H2O. Heating to about 70 Deg causes the formate to decomp. exclusively where the surface had been seeded with the thin film of platinum clusters. Line resistivities of about twice that of pure bulk copper can be obtained in this way. In principle this method should permit direct writing of metal stripes at very high speeds and good spatial resoln.