A baler apparatus (10) for forming and enveloping a cylindrical bale (11) having a cylindrical outer surface (13) and a pair of opposed circular end faces (14), and which comprises: a bale-forming chamber (12) having opposed side walls (19); means (30) for supplying material to be baled to the chamber (12); rollers, belts or like engaging means (12a) arranged around the periphery of the chamber (12) to assist in the formation of a bale (11); means for applying an elongate strip of wrapping material (16) to the bale (11), such strip being of greater width than the axial extent of the bale and having a main portion which is guided to overlie the cylindrical surface (13) of the bale (11), and a pair of opposed marginal portions which are guided so as to fold radially inwardly with respect to the axis (15) of the bale (11) and to engage each with at least an outer circumferential region of a corresponding circular end face (14) of the bale (11); and at least one guiding device (20, 21) rotatably mounted on each side wall (19) of the chamber (12) and engageable with at least part of the adjacent end face (14) of the bale (11), prior to application of the strip of enveloping material (16), in order to urge said part of the end face (14) axially away from the side wall (19); and the guiding device (20, 21) optionally also being engageable with a respective marginal portion of the strip of enveloping material (16) to urge the latter axially away from the side wall (19). <;IMAGE>;