A method is disclosed for altering an implantable layer for use with a surgical instrument which includes the steps of obtaining an implantable layer comprised at least partially from a material including a glass transition temperature and a melting temperature, wherein the implantable layer includes a first shape, heating the material to a temperature higher than the glass transition temperature and lower than the melting temperature, manipulating the implantable layer to a second shape different than the first shape, allowing the material to cool below the glass transition temperature, and releasing the implantable layer.
