Abstract: Treatment of the inner and outer surfaces of an orifice plate for ink-jet pens with self-assembled monolayers is disclosed. The outer surface of a gold-plated orifice plate is treated with self-assembled monolayers to control wettability of the surface in order to reduce the accumulation of residual ink. The inner surface is treated with self-assembled monolayers to improve and control drop ejection. Various monolayers can also be used on the inner surface allowing for greater flexibility in controlling the steady state firing rate and uniformity of drops from a pen. In addition, treatment of orifice plate surfaces with self-assembled monolayers inhibits corrosion and contamination of the plate while presenting a uniform surface for the ink. The self-assembled monolayers for use in the present invention include thiols, disulfides, and sulfinates, having terminal functional groups which determine the wettability of the surface.