A staple cartridge assembly includes, one, a plurality of staples movable between unfired positions and fired positions and, two, a layer, such as a tissue thickness compensator and/or a buttress material, for example, wherein the staples are configured to at least partially capture the layer when the staples are moved between the unfired positions and the fired positions. The layer can include a cushioning member at least partially extending around a peripheral portion of the tissue thickness compensator. The layer can include features which create a flexible transition between the tissue supported by the layer and the staples and the unsupported tissue.