Surgical stapling instruments are disclosed. At least one embodiment includes a first jaw that supports a plurality of surgical staples and a second jaw that is movable relative to the first jaw. Various arrangements include a tissue thickness compensator that is configured to be captured within the surgical staples and assume different compressed heights within different surgical staples upon application of a firing motion to the surgical staples. Various attachment protrusion arrangements are disclosed to mechanically removably attach the tissue thickness compensator to the first or second jaw.
