TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The step (a) involves providing a substrate including graphene oxide on its surface. The substrate in step (a) includes a layer of graphene oxide on the surface. The dispersion of graphene oxide comprises a dispersion of graphene oxide in water. The layer of reduced or partially reduced graphene oxide is produced on the surface. The reducing agent is selectively applied to the layer of graphene oxide such that the layer of reduced or partially reduced graphene oxide forms a pattern in the graphene oxide layer. The step (a) includes coating or depositing graphene oxide dispersion onto the surface of the substrate. The reducing agent at step (b) is applied as part of a solution. The step (b) includes immersing or dip coating the substrate surface including the graphene oxide in the solution including the reducing agent. The step (b) involves printing the solution including the reducing agent on to the substrate including the graphene oxide. The printing includes gravure, roll-to-roll, reel-to-reel, inkjet or flexographic printing. Preferred Components: The solution includes the reducing agent is an aqueous solution. The applied reducing agent is ascorbic acid. The conductivity of the reduced or partially reduced graphene oxide is 0-5000 S/cm. The reduced or partially reduced graphene oxide is in the form of a circuit pattern. EXAMPLE - Initial graphene oxide (GO) material was prepared by modified Hummers method, via the reaction of graphite with a mixture of potassium permanganate and concentrated sulfuric acid. Dispersions of this GO material (0.5%) were then made by dispersing the GO flakes in pure Milli-Q water without any surfactant by low medium power sonication for 60 minutes. A slurry-style dispersion of GO (1-2%) was made by partially evaporating the Milli-Q (RTM: water purifier), water under vigorous stirring. Graphene oxide (GO) powder was prepared using modified Hummer's method, and dispersed in pure Milli-Q water (1 to 5 mg/ml, without any surfactant) in a bottle via ultrasonication for 60 minutes. The dispersion was then directly transferred onto a hot-plate at 60 degrees C and allowed continuous strong stirring until it changed to slurry-style dispersion (with volume change from 50 ml down close to 10 ml). The slurry-style dispersion was then used for preparing GO films. Thin GO films (brown color) were coated onto different substrates (both rigid and flexible) using prepared slurry-style dispersion by knife-blading and/or vacuum spray methods, followed by immediately drying in a vacuum oven at 150 degrees C in order to evaporate the water trapped in the wet GO films. As-prepared GO film coated substrates were immersed into ascorbic acid (reducing agent) solution with different concentrations (reGO1 with 0.1 M ascorbic acid, reGO2 with 0.2 M ascorbic acid and reGO3 with 0.5 M ascorbic acid) in order to obtain the reduced GO films with different electronic conductivities (related to different reduced levels). Then the reduced graphene oxide (reGO) films (black color) were washed with both Milli-Q water and ethanol in order to remove the remaining salt (due to absorption) followed by a vacuum oven dry at 120 degrees C for 30 minutes.