Releasable tissue thickness compensator and fastener cartridge having the same

A fastener cartridge can comprise a cartridge body comprising fastener cavities, fasteners at least partially stored within the cartridge body, and a layer positioned over the cartridge body. The cartridge body can include a proximal end and a distal end. Similarly, the layer can include a proximal end and a distal end. The distal end of the layer can extend distally with respect to the distal end of the cartridge body. Furthermore, the layer can include a distal portion which extends distally with respect to the fastener cavities defined in the cartridge body. This distal portion can be positioned against the tissue being fastened and can flexibly support the tissue after the layer has been implanted against the tissue. The layer may include a proximal portion which extends proximally with respect to the fastener cavities which can flexibly support the tissue after the layer has been implanted.