Provided is a printhead cartridge for a pagewidth printer. The cartridge includes a cartridge body having a base and a number of ink supply bags positioned inside the base. A lid encloses the bags in the base. The cartridge also includes a printhead assembly fast with the base and arranged in fluid communication with the ink bags. Each ink supply bag has two profiled panels sealed together to form an ink holding chamber which is collapsible to reduce a volume of ink stored therein. A folded leaf spring biases the chamber into an expanded condition. Each ink bag also includes a connector assembly providing fluid communication between the chamber and ink supply channels of the printhead assembly.