Method of providing printhead assembly having complementary hydrophilic and hydrophobic surfaces

A method of providing a printhead assembly having a hydrophilic ink pathway and a hydrophobic ink ejection face, the method comprising the steps of:

• providing a printhead assembly having an inkjet printhead attached to an ink supply manifold, the printhead comprising a nozzle plate having a hydrophobic coating and a protective metal film disposed on the hydrophobic coating;
• treating surfaces of an ink pathway in the printhead assembly with a solution comprising an alkoxylated polyethyleneimine;
• drying the surfaces;
• and
• removing the protective metal film so as to reveal the hydrophobic coating, thereby providing the printhead assembly having the hydrophilic ink pathway and the hydrophobic ink ejection face.