Tissue stapler having a thickness compensator

A staple cartridge, comprising:

• a cartridge deck;
• a longitudinal slot within said staple cartridge and configured to receive a firing member, wherein the firing member moves within said staple cartridge during a firing stroke;
• staple cavities defined in said deck;
• staples removably stored in said staple cavities;
• staple drivers configured to support said staples within said staple cavities;
• a sled comprising a plurality of ramps configured to engage said staple drivers;
• and
• a tissue thickness compensator supported over said cartridge deck, wherein said tissue thickness compensator comprises:
• a body portion;
• and
• upwardly-extending bumps, wherein said bumps are configured to engage tissue in order to limit movement between the tissue and said body portion.

A staple cartridge assembly, comprising:

• a cartridge deck;
• projections extending from said deck;
• staple cavities defined in said cartridge deck;
• staples removably stored in said staple cavities, wherein each said staple comprises staple legs;
• staple drivers configured to push said staples out of said staple cavities;
• a sled comprising a plurality of ramps configured to engage said staple drivers during a firing stroke;
• a longitudinal slot defined within said staple cartridge, wherein said longitudinal slot is configured to receive a firing member to advance said sled through said firing stroke;
• and
• an adjunct configured on said cartridge deck, wherein said adjunct comprises:
• a body portion extending over said staple cavities;
• and
• bumps extending over said staple legs.