For various embodiments of a printhead assembly or ink stick assembly of the present teachings, each an ink stick assembly can be a self-contained assembly, of which a plurality of self-contained ink stick assemblies can be readily interchanged into a printing system during a printing process. Various embodiments of a self-contained ink stick assembly can have a fluidic system that can include a local ink reservoir, which can be in fluid communication with a bulk ink reservoir. Filling of a bulk ink reservoir can be done in a manual or automated mode. According to the present teachings, a bulk ink reservoir can have a volume sufficient to provide a continuous supply of ink to a local ink reservoir over the course of a printing process.