An apparatus, the apparatus comprising: (a) a body assembly; (b) a shaft extending distally from the body assembly; (c) an end effector attached to the shaft, wherein the end effector comprises: (i) a jaw, (ii) an anvil pivotable from an open position to a closed position relative to the jaw, and (iii) a knife member configured to translate relative to the anvil in order to sever tissue; and (d) a cartridge releasably engaged with the jaw, wherein the cartridge defines a longitudinal channel, wherein the knife member is configured to translate within the longitudinal channel, wherein the cartridge comprises: (i) a deck comprising an upper surface facing toward the anvil, (ii) a buttress assembly, wherein a first portion of the buttress assembly is positioned on top of the deck, wherein a second portion of the buttress assembly is positioned within the longitudinal channel, wherein the first portion and the second portion are connected to each other, and (iii) a folding sled comprising a folding member, wherein the folding member is configured to translate within the longitudinal channel in order to move the second portion of the buttress assembly to a position that is above the deck characterised in that the folding member is located proximally in relation to a distal end of the knife member in the channel. (a) a body assembly; (b) a shaft extending distally from the body assembly; (c) an end effector attached to the shaft, wherein the end effector comprises: (i) a jaw, (ii) an anvil pivotable from an open position to a closed position relative to the jaw, and (iii) a knife member configured to translate relative to the anvil in order to sever tissue; and (i) a jaw, (ii) an anvil pivotable from an open position to a closed position relative to the jaw, and (iii) a knife member configured to translate relative to the anvil in order to sever tissue; and (d) a cartridge releasably engaged with the jaw, wherein the cartridge defines a longitudinal channel, wherein the knife member is configured to translate within the longitudinal channel, wherein the cartridge comprises: (i) a deck comprising an upper surface facing toward the anvil, (ii) a buttress assembly, wherein a first portion of the buttress assembly is positioned on top of the deck, wherein a second portion of the buttress assembly is positioned within the longitudinal channel, wherein the first portion and the second portion are connected to each other, and (iii) a folding sled comprising a folding member, wherein the folding member is configured to translate within the longitudinal channel in order to move the second portion of the buttress assembly to a position that is above the deck characterised in that the folding member is located proximally in relation to a distal end of the knife member in the channel. (i) a deck comprising an upper surface facing toward the anvil, (ii) a buttress assembly, wherein a first portion of the buttress assembly is positioned on top of the deck, wherein a second portion of the buttress assembly is positioned within the longitudinal channel, wherein the first portion and the second portion are connected to each other, and (iii) a folding sled comprising a folding member, wherein the folding member is configured to translate within the longitudinal channel in order to move the second portion of the buttress assembly to a position that is above the deck characterised in that the folding member is located proximally in relation to a distal end of the knife member in the channel.