An adjunct material for use with an end effector in a surgical instrument is provided that has at least one projection configured to mate with a corresponding recess formed in at least one jaw, such as a cartridge or anvil, of the end effector. The at least one projection can be one or more discrete projections or longitudinal projection(s) extending between distal and proximal ends of the adjunct material. An applicator member can be used to apply force to the adjunct material to thus cause the adjunct material to mate with the jaw of the end effector. The applicator member can be configured told the adjunct material and can be clamped between the jaws of the end effector to release the adjunct material onto the jaw. Also, an applicator member can be used to push portions of an adjunct material into corresponding recesses in a jaw.
