Cassette half having multi-layer molded construction

A cassette half comprising:

• a first molded body having a first principal surface and a first upstanding wall which is substantially perpendicular to said first principal surface, said first upstanding wall forming an integral part of said first principal surface and a part of a peripheral surface of said half;
• a second molded body overlying said first molded body, said second molded body having a second principal surface which overlies said first principal surface, said second molded body having a second upstanding wall which is essentially perpendicular to said second principal surface, said second upstanding wall forming an integral part of said second principal surface and surrounding said second principal surface, said second upstanding wall forming part of the peripheral surface of said half, said second upstanding wall connecting with said first upstanding wall to form a complete peripheral surface of said half, said first and second upstanding walls being connected over a junction area so that, in a plane defined by a surface of said upstanding walls, the respective thickness of the first upstanding wall and the thickness of the second upstanding wall gradually vary in a manner wherein a sum of the thicknesses of said first and second upstanding walls, as measured in said plane, remains constant and equal to the thickness of said cassette half over said junction area.