A forming pocket which is suitable for receiving particulate material and forming conglomerates from the particulate material to be used as an absorbent filler for sanitary products comprises: an external forming substrate (3) which is suitable for receiving particulate material which is it is provided with openings and has a shape in conjunction with the shape of the absorbent filler to be made； a grid-shaped support structure (10； 30) which is coupled to the external substrate (3) for supporting said external substrate (3) during suction of the particulate material through the external substrate (3) and comprises an outer face (11) for contact with the outer substrate (3) and in a shape in conjunction with the shape of the outer substrate (3), an inner face (12), opposite the outer face (11), a pair of upper side faces ( 13) which are opposite each other and a pair of opposite side faces (14) which are opposite each other, and through openings (17a, 17b, 18a, 18b) extending between the outer face (11) and the inner face ( 12) to allow gas to flow from the outer face (11) to the inner face (12) during said suction. One method of making the forming pocket comprises manufacturing at least one outer layer (15) of the support structure (10； 30) and at least one inner layer (16) of the support structure (10； 30) which are overlapped. and have respectively external openings (17a, 17b) and internal openings (18a, 18b) limited by the outer walls (19a, 19b) and the inner walls (20a, 20b), in which the outer openings (17a, 17b) and the openings internals (18a, 18b) are arranged overlapping to define said through openings (17a, 17b, 18a, 18b)； and wherein the method further comprises making at least one of the outer openings (17a, 17b) of a different shape and / or dimension than one of the inner openings (18a, 18b) in which it is overlapped using an additive layer manufacturing process, that is, 3d printing to make outer walls (19a, 19b) and inner walls (20a, 20b).um bolso d
