Inkjet printing systems often utilize one or more replaceable ink containers that hold a finite volume of ink. An ink container can be replaced if the ink container is unable to deliver ink. For example, an ink container can be replaced if all of the ink in the ink container is used and the ink container is empty. Many known ink containers are unable to deliver all of the ink in the ink container and are considered to be effectively empty although some ink remains in the ink container. Such ink containers can be replaced when the ink container ceases to adequately deliver ink. Users generally prefer ink containers that do not have to be frequently replaced. Furthermore, users generally prefer ink containers that are relatively easy to replace when replacement is necessary.