A floor panel, comprising: a decorative layer, and a core layer (10, 11) arranged below the decorative layer when the floor panel is substantially horizontally oriented, and a balancing layer, wherein the core layer is sandwiched between the balancing layer and the decorative layer, wherein the core layer comprises a plurality of wood blocks arranged with their respective principal fiber directions substantially parallel with a plane (So) defined by a major surface of the floor panel and substantially perpendicular to a principal direction of the floor panel, and a plurality of second material blocks, made from a different material than said wood blocks, characterized in that along the principal direction of the floor panel, the core layer presents alternating portions formed of said wood blocks and of said second material blocks, the second material blocks have lower density than said wood blocks and/or lower tensile strength in a direction parallel to said principal fiber direction than said wood blocks, the wood blocks comprise wood blocks of a wood quality, which is: lower than or equal to V according to the Swedish "Gröna boken" ("The Green book") standard of 1960, preferably lower than or equal to VI or lower than or equal to VII; lower than or equal to B according to the Swedish "Blåa boken" ("The Blue book") standard of 1994, preferably lower than or equal to C or lower than or equal to D; and/or lower than or equal to G4-2/G2-2 of the European EN 1611-1 standard of 2000, preferably lower than or equal to G4-3/G2-3 or lower than or equal to G4-4/G2-4. a decorative layer, and a core layer (10, 11) arranged below the decorative layer when the floor panel is substantially horizontally oriented, and a balancing layer, wherein the core layer is sandwiched between the balancing layer and the decorative layer, wherein the core layer comprises a plurality of wood blocks arranged with their respective principal fiber directions substantially parallel with a plane (So) defined by a major surface of the floor panel and substantially perpendicular to a principal direction of the floor panel, and a plurality of second material blocks, made from a different material than said wood blocks, characterized in that along the principal direction of the floor panel, the core layer presents alternating portions formed of said wood blocks and of said second material blocks, the second material blocks have lower density than said wood blocks and/or lower tensile strength in a direction parallel to said principal fiber direction than said wood blocks, the wood blocks comprise wood blocks of a wood quality, which is: lower than or equal to V according to the Swedish "Gröna boken" ("The Green book") standard of 1960, preferably lower than or equal to VI or lower than or equal to VII; lower than or equal to B according to the Swedish "Blåa boken" ("The Blue book") standard of 1994, preferably lower than or equal to C or lower than or equal to D; and/or lower than or equal to G4-2/G2-2 of the European EN 1611-1 standard of 2000, preferably lower than or equal to G4-3/G2-3 or lower than or equal to G4-4/G2-4. lower than or equal to V according to the Swedish "Gröna boken" ("The Green book") standard of 1960, preferably lower than or equal to VI or lower than or equal to VII; lower than or equal to B according to the Swedish "Blåa boken" ("The Blue book") standard of 1994, preferably lower than or equal to C or lower than or equal to D; and/or lower than or equal to G4-2/G2-2 of the European EN 1611-1 standard of 2000, preferably lower than or equal to G4-3/G2-3 or lower than or equal to G4-4/G2-4.