A substantially planar absorbent core (28) comprising a core wrap (16, 17) enclosing an absorbent material (60), the absorbent core having a longitudinal axis (80) and comprising a front region (81), a back region (83) and a middle region (82). The absorbent material is substantially free of cellulose fibers and forms a pattern of discrete absorbent material areas. The core further comprises at least a pair of curved longitudinally-extending channel-forming areas (26a, 26b) substantially free of absorbent material, through which the top side (288) of the core wrap is attached to the bottom side (290) of the core wrap along a core wrap bond (27). When the absorbent material areas adjacent the channel-forming areas (603, 604) absorb a fluid and swells, three-dimensional channels (260) are formed along the core wrap bond (27). The channel-forming areas are disposed on opposite side of the longitudinal axis. Each of the longitudinally-extending channel-forming areas (26a, b) are longitudinally flanked internally by a first flanking absorbent material area (603a, 603b) and externally by a second flanking absorbent material area (604a, 604b), the first and second flanking absorbent material areas following the curvature of the channel-forming area.
