A container (10) is formed from a piece of material having at least two layers, a first layer (12) having a first end and an opposite end, and a second layer (14) having a first end and an opposite end, the first and second layers being fixed to one another such that the respective first ends of each of the layers are spaced apart from one another to form a first step (28) and the respective second ends of each of the layers are spaced apart from one another to form a second step (26), the steps being complementary to one another and being adhered together to form a join (16,18), characterised in that the outer join line (18) is of one shape and the inner join line (16) is of a second, different, shape.