Barrier paper or board

A process for improving the barrier properties of a barrier layer comprised in a pulp-based substrate layer having a barrier layer, comprising the steps of

• a) providing a pulp-based substrate layer having a layer of an aqueous barrier composition applied to it,
• b) drying the pulp-based substrate layer having a layer of aqueous barrier composition applied to it to form a pulp-based substrate layer having a barrier layer, such that the moisture content of the pulp-based substrate layer having a barrier layer is below 2.5% by weight, based on the weight of the pulp-based substrate layer having a barrier layer.

A packaging material comprising at least one pulp-based substrate layer having, in this order,

• optionally a primer layer adjacent to the pulp-based substrate layer,
• a first barrier layer adjacent to the pulp-based substrate layer or the primer layer,
• optionally a sealing layer such as a heat- or cold-sealing layer adjacent to the first barrier layer, wherein the amount of the first barrier layer ranges from 4 gsm to 11 gsm, and wherein the packaging material exhibits a WVTR at tropical conditions (38° C., 90% RH) of 1 to 5 g/(m2·d).