A method is described of producing thin layers (below 10 .mu.m in thickness) by directing droplets (preferably by inkjet printing techniques) onto precise locations on a substrate, the liquid of the droplets having a viscosity such that the droplets, on impact with the substrate, spread out to form relics on the substrate that are at least 1.4 times the diameter of the droplets in flight, adjacent droplets merging to form a continuous layer on the substrate. The droplets may have different compositions to form images within the layer. Successive layers may be added to built up a three dimensional structure whose properties can be tailored by the compositions used to build up a composite.