Core layer, wherein the core layer comprises wooden zigzag-shaped elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) comprising zigzagging laminar regions (20, 30), wherein a zig region of an element (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12), together with an adjoining zag region of the zigzag-shaped element (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12), form between them a common edge (1', 2', 3', 4', 6'), and wherein zigzag-shaped elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) are arranged in the core layer such that two such edges (1', 2', 3', 4', 6') of two zigzag-shaped elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12), which can be the same or different from each other, intersect at an angle which is different from zero, the two elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) being fixedly connected to each other at the point of intersection; wherein the wooden elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) have in the core layer one or more of the following arrangements (a) to (d): (a) the laminar regions (20, 30) of the wooden elements (1, 5) are planar regions and the edge formed between the planar regions is a planar region; (b) the laminar regions (20, 30) of the wooden elements (2, 6) are curved regions and the edge formed between the curved regions is a curved region; (c) the laminar regions (20, 30) of the wooden elements (3, 7) are curved regions and the edge formed between the curved regions is a straight line; (d) the laminar regions (20, 30) of the wooden elements (4, 8) are curved regions and the edge formed between the curved regions is a planar region; and wherein (α) the wooden elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) are randomly distributed in the core layer; or (β) the wooden elements are randomly arranged in the core layer side by side and one above the other; or (γ) the wooden elements are randomly arranged in the core layer, and the edges intersect at different angles; characterized in that said zigzag-shaped wooden elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) comprise fibres having a preferred direction, wherein the common edge (1', 2', 3', 4', 6') or the common edges (1', 2', 3', 4', 6') runs or run non-parallel to the preferred direction; or wherein the common edge (1', 2', 3', 4', 6') or the common edges (1', 2', 3', 4', 6') runs or run perpendicular to the preferred direction. (a) the laminar regions (20, 30) of the wooden elements (1, 5) are planar regions and the edge formed between the planar regions is a planar region; (b) the laminar regions (20, 30) of the wooden elements (2, 6) are curved regions and the edge formed between the curved regions is a curved region; (c) the laminar regions (20, 30) of the wooden elements (3, 7) are curved regions and the edge formed between the curved regions is a straight line; (d) the laminar regions (20, 30) of the wooden elements (4, 8) are curved regions and the edge formed between the curved regions is a planar region; (α) the wooden elements (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) are randomly distributed in the core layer; or (β) the wooden elements are randomly arranged in the core layer side by side and one above the other; or (γ) the wooden elements are randomly arranged in the core layer, and the edges intersect at different angles;