Fluid cartridge for an inkjet printer

A fluid cartridge for an inkjet printer, the cartridge comprising:

• an inner reservoir containing a printing fluid, the reservoir comprising walls enclosing an internal space having a variable volume for storage of the printing fluid and a port for dispensing the printing liquid, wherein the reservoir comprises a rigid framework and one or more elastically deformable sections,
• an outlet for connection to the printer;
• an outer housing in which the reservoir is housed;
• an electronic storage device configured to store data relating to the contents of the cartridge;
• and
• at least one electrical contact associated with the electronic storage device and provided on a substrate, wherein the substrate is fixed relative to the outlet by a pocket defined on the inside of the housing and the pocket comprises at least one locking element having slots for supporting edges of the substrate;
• wherein the rigid framework and one or more elastically deformable sections of the reservoir provide a reduction in pressure of the internal space whereby the equilibrium pressure difference between the internal space and the surrounding atmosphere increases substantially monotonically in magnitude as liquid is dispensed,
• wherein the port is adapted to allow liquid to be dispensed when a withdrawal pressure at the exterior of the port is less than the equilibrium pressure of the internal space,
• and wherein the port is adapted to prevent air from entering the internal space from outside the reservoir as liquid is dispensed,
• wherein the container is for storing and dispensing ink or solvent for use with a continuous inkjet printer.