A bellows capping system is provided for sealing ink-ejecting nozzles of an inkjet printhead in an inkjet printing mechanism, such as a printer, during periods of printing inactivity. The system includes a support which moves between a sealing position and a rest position. The system also has a cap which extends from the support and terminates in a lip. The lip surrounds the nozzles when the support is in the sealing position. The cap has a wall with first and second leg portions joined together at a knee portion between the support and the lip. When sealing the printhead, the knee bends or buckles so the first and second portions collapse toward each other. Multiple knee portions may join together multiple wall portions in a bellows or accordion arrangement. An inkjet printing mechanism having the bellows capping system and method of using this capping system are also provided.