An ink cartridge includes an ink-holding portion and a rigid upper surface. The ink-holding portion includes a rigid indented surface portion and a flexible film. The indented surface portion has an open side at one side thereof that is covered by the flexible film. Ink is accommodated between the indented...http://www.google.se/patents/US7226153?utm_source=gb-gplus-sharePatent US7226153 - Ink cartridge
