Liquid toners suitable for use in the electrostatic printing of functional materials to produce microstructures such as ribs, electrodes, spacers or filters, and methods of producing the liquid toners. The functional materials, which may include metals, glass and phosphors, are suspended as particles in a dilutent, which may be a non-polar liquid. The surface, or portions of the surface, of the functional material particles are given an appropriate acidic or hydroxyl functionality necessary for their use in electrostatic imaging either by etching or by coating with a material having the appropriate surface functionality.