An end effector for use with a surgical stapler, the end effector comprising: a staple cartridge having a tissue contacting surface, a first side surface and a second side surface opposite the first side surface; an anvil plate having a tissue contacting surface, a first side surface and a second side surface opposite the first side surface; a cartridge buttress releasably disposed on the tissue contacting surface of the staple cartridge; an anvil buttress releasably disposed on the tissue contacting surface of the anvil plate; a proximal cartridge anchor member passing transversely across a proximal portion of the cartridge buttress; a distal cartridge anchor member passing transversely across a distal portion of the cartridge buttress; a proximal anvil plate anchor member passing transversely across a proximal portion of the anvil buttress; a distal anvil plate anchor member passing transversely across a distal portion of the anvil buttress, characterized in that: the first and second side surfaces of the staple cartridge have overmolded zones (242a,242b,244a,244b) made from a polymeric material disposed near a proximal and distal portion thereof; the first and second side surfaces of the anvil plate have overmolded zones (332a,332b,334a,334b) made from a polymeric material disposed near a proximal and distal portion thereof; first and second ends of the proximal cartridge anchor member are bonded to the respective proximal overmolded zones (244a,244b) of the first and second side surfaces of the staple cartridge; first and second ends of the distal cartridge anchor member are bonded to the respective distal overmolded zones (242a,242b) of the first and second side surfaces of the staple cartridge; first and second ends of the proximal anvil plate anchor member are bonded to the respective proximal overmolded zones (334a,334b) of the first and second side surfaces of the anvil plate; and first and second ends of the distal anvil plate anchor member are bonded to the respective distal overmolded zones (332a,332b) of the first and second side surfaces of the anvil plate. a staple cartridge having a tissue contacting surface, a first side surface and a second side surface opposite the first side surface; an anvil plate having a tissue contacting surface, a first side surface and a second side surface opposite the first side surface; a cartridge buttress releasably disposed on the tissue contacting surface of the staple cartridge; an anvil buttress releasably disposed on the tissue contacting surface of the anvil plate; a proximal cartridge anchor member passing transversely across a proximal portion of the cartridge buttress; a distal cartridge anchor member passing transversely across a distal portion of the cartridge buttress; a proximal anvil plate anchor member passing transversely across a proximal portion of the anvil buttress; a distal anvil plate anchor member passing transversely across a distal portion of the anvil buttress, the first and second side surfaces of the staple cartridge have overmolded zones (242a,242b,244a,244b) made from a polymeric material disposed near a proximal and distal portion thereof; the first and second side surfaces of the anvil plate have overmolded zones (332a,332b,334a,334b) made from a polymeric material disposed near a proximal and distal portion thereof; first and second ends of the proximal cartridge anchor member are bonded to the respective proximal overmolded zones (244a,244b) of the first and second side surfaces of the staple cartridge; first and second ends of the distal cartridge anchor member are bonded to the respective distal overmolded zones (242a,242b) of the first and second side surfaces of the staple cartridge; first and second ends of the proximal anvil plate anchor member are bonded to the respective proximal overmolded zones (334a,334b) of the first and second side surfaces of the anvil plate; and first and second ends of the distal anvil plate anchor member are bonded to the respective distal overmolded zones (332a,332b) of the first and second side surfaces of the anvil plate.