Paper or paperboard laminate and method of producing such a laminate

A paper or paperboard laminate composed of at least one bulk-promoting layer, here termed bulk layer (1), 40-98% of which is composed of cellulose fibres with a freeness value of 550-950 ml CSF, and on at least one side of the bulk layer at least one secondary layer (3a, 3b′), which has a greater density than the bulk layer, the secondary layer and bulk layer being joined indirectly to one another over basically the whole of their opposing surfaces and the laminate having a bending stiffness index greater than 2.5 Nm7/kg3, but less than 14 Nm7/kg3, calculated as a geometric mean value for machine direction and cross direction, characterised in that a thin intermediate layer (2a), which has a higher drainage resistance than the bulk layer (1), and which has a basis weight of at least 2 g/m2 but less than 20 g/m2 and which has been formed together with the bulk layer, is arranged between the said bulk layer (1) and secondary layer (3a, 3b′).