An end effector is disclosed which comprises a first jaw, a second jaw, a staple cartridge, an anvil, and at least one layer positioned intermediate the first jaw and the second jaw. The layer may include a pattern of holding features defined on a tissue contacting surface of the layer. The pattern of holding features can extend between a proximal end of the layer and a distal end of the layer. The pattern of holding features may be defined by a network of interconnected channels skew to a longitudinal axis of the layer. The network of interconnected channels may be configured to mitigate and/or control the flow of patient tissue relative to the layer.