A wiring board includes a substrate including a first main surface, a second main surface, a side surface, and an inclined surface connecting the first main surface and the side surface, and side wiring on the first main surface, the inclined surface, and the side surface. The side wiring has a content of conductive particles greater than a content of an insulating component, and the wiring has a thickness equal to a thickness of at least one of the conductive particles in a first corner between the first main surface and the inclined surface and in a second corner between the inclined surface and the side surface.

Provided herein are conductive inks and methods of formulation thereof, whose electric and mechanical properties (e.g., viscosity and surface tension) enable its use in a wide array of printing techniques. The outstanding conductivity, thermal stability, chemical stability, and flexibility of graphene in the inks herein enable the production of low-cost electronics with tunable electrochemical properties.