Layer of material for a surgical end effector

A staple cartridge assembly, comprising:

• a staple cartridge, comprising:
• a cartridge deck;
• staple cavities;
• and
• a plurality of staples stored in said staple cavities, wherein said staples are deformable to a formed height;
• an implantable adjunct capable of being positioned on said cartridge deck, comprising:
• a first woven construct;
• and
• a second woven construct, wherein said first woven construct comprises a first density and said second woven construct comprises a second density different than said first density, and wherein said implantable adjunct is configured to expand upon contact with a fluid in order to adapt to a thickness of tissue captured within said staples.

A staple cartridge, comprising:

• a cartridge deck;
• staple cavities;
• a plurality of staples stored in said staple cavities, wherein said staples are deformable to a formed height;
• and
• an implantable layer positionable on said cartridge deck, comprising:
• a first woven, fiber construct;
• and
• a second woven, fiber construct, wherein said first woven, fiber construct comprises a first density and said second woven, fiber construct comprises a second density which is different than said first density, and wherein said implantable layer is configured to expand upon contact with a fluid in order to apply a compressive force to tissue captured within said staples.