Abstract: A casing for holding a magnetic tape cassette which is formed into a box shape by bending and joining a blank of a transparent blastic plate material which has one surface, constituting the inner surface of a casing, on which grooves and a minutely roughened area are provided except for on a predetermined portion including at least one transparent window and the other surface, constituting the outer surface of said casing, on which printing and/or an uneven surface pattern is provided in a predetermined portion except for said transparent window.

Abstract: The disclosure described a casing for a magnetic tape cassette having a transparent window which is formed by laminating a bonding layer of a plastic sheet of the same material as a casing body and a reinforcing layer of a plastic sheet of the different material from the bonding layer.

Abstract: A casing for holding a magnetic tape cassette which is formed into a box shape by bending and joining a blank of a transparent .[.blastic.]. .Iadd.plastic .Iaddend.plate material which has one surface, constituting the inner surface of a casing, on which grooves and a minutely roughened area are provided except for on a predetermined portion including at least one transparent window and the other surface, constituting the outer surface of said casing, on which printing and/or an uneven surface pattern is provided in a predetermined portion except for said transparent window.