Package comprising a tray-shaped bottom part and a cover

A package comprising a tray-shaped bottom part (1, 41, 81) provided with an opening covered by a cover (2,42,82) sealed to the bottom part along a circumferential rim (10,50,90) thereof to form a sealed compartment, and wherein the cover (2, 42, 82) to form a peelable cover part (15, 55, 95) is sealed peelably to the bottom part along a portion of the rim thereof by means of a first sealing line (20) extending between two terminal points (21,22) arranged on a line (23) extending across the opening of the bottom part (1, 41, 81), and wherein the cover (2,42,82) is sealed firmly to the rim (10,50,90) of the bottom part (1,41,81) by means of other sealing lines (27) at least in the rim portions of the bottom part immediately adjacent said points, and wherein the cover part (2, 42, 82) at least in the portion of said line (23) is formed of a first flexible plastic sheet (14,54,94), characterised in that the peelable cover part (15, 55, 95) is formed more rigidly than the first plastic sheet (14, 54, 94) and comprises a rigidity-increasing further sheet (16, 73, 96) sealed firmly to the first sheet (14, 54, 94), and that the rigidity-increasing sheet (16, 73, 96) extends essentially over the entire peelable cover part (15,55,95).