A surgical stapler, comprising: a staple cartridge channel configured to receive a curved staple cartridge, the staple cartridge configured to removably store staples therein; an anvil configured to deform said staples; said staple cartridge; and a curved piece of buttress material, wherein said staple cartridge comprises: a surface configured to receive said curved piece of buttress material thereon, wherein said surface includes a first end, a second end, and a first edge extending between said first end and said second end, and wherein said first edge is at least partially defined by a first radius of curvature, wherein said surface further includes a second edge extending between said first end and said second end, wherein said second edge is at least partially defined by a second radius of curvature; said piece of buttress material, comprising: a first buttress material end; a second buttress material end; a first buttress material edge extending between said first buttress material end and said second buttress material end; and a second buttress material edge extending between said first buttress material end and said second buttress material end, wherein said first buttress material edge is at least partially defined by said first radius of curvature, and said second buttress material edge is at least partially defined by said second radius of curvature, a first lip which extends along said first edge, wherein said first lip is configured to reduce relative movement between said piece of buttress material and said surface; and a second lip which at least partially extends along said second edge, wherein the first lip is longer than the buttress material and limits relative axial movement between the buttress material and the staple cartridge. a staple cartridge channel configured to receive a curved staple cartridge, the staple cartridge configured to removably store staples therein; an anvil configured to deform said staples; said staple cartridge; and a curved piece of buttress material, a surface configured to receive said curved piece of buttress material thereon, wherein said surface includes a first end, a second end, and a first edge extending between said first end and said second end, and wherein said first edge is at least partially defined by a first radius of curvature, wherein said surface further includes a second edge extending between said first end and said second end, wherein said second edge is at least partially defined by a second radius of curvature; said piece of buttress material, comprising: a first buttress material end; a second buttress material end; a first buttress material end; a second buttress material end; a first buttress material edge extending between said first buttress material end and said second buttress material end; and a second buttress material edge extending between said first buttress material end and said second buttress material end, wherein said first buttress material edge is at least partially defined by said first radius of curvature, and said second buttress material edge is at least partially defined by said second radius of curvature, a first lip which extends along said first edge, wherein said first lip is configured to reduce relative movement between said piece of buttress material and said surface; and a second lip which at least partially extends along said second edge, wherein the first lip is longer than the buttress material and limits relative axial movement between the buttress material and the staple cartridge.