Felt material (1) comprising a multitude of fibers (2) for use in a method of repairing or augmenting human or animal soft tissues (3), wherein the felt material (1) is in the form of a matting or felted patch (9) comprising a first surface (5) and oppositely arranged a second surface (6) for contacting a surface of soft tissue (3), and wherein some of the fibers (2) of the felted patch (9) are pushed or pulled through the second surface (6) into the soft tissue (3) by means of a needle (10) producing a connection between the felt material (1) and the soft tissue (3). Further, a set of instruments is provided which comprises a needle (10), a stitching device (30) and a clamping device (20) comprising a first jaw (21a) which is frame-like configured permitting the tip portion of the needle (10) to penetrate the first jaw (21a) and a second jaw (21b) with a cavity (29) configured to receive the tip portion of the needle (10).