A multi-layered (co)extruded thermoplastic food casing comprising: at least one thermoplastic porous absorbing layer and at least one layer having a barrier effect for water vapour and/or oxygen, wherein said at least one layer having a barrier effect for water vapour and/or oxygen has an average layer thickness in a range of from 5 to 60 μm over the entire surface area, characterized in that said at least one thermoplastic porous absorbing layer comprises as a main component at least one thermoplastic polymer material selected from the group consisting of (co)polyamides and (co)polyolefins, wherein said at least one thermoplastic porous absorbing layer comprises areas having a reduced average layer thickness and areas having a non-reduced average layer thickness, wherein the average layer thickness of said at least one thermoplastic porous absorbing layer in areas having a non-reduced average layer thickness is in a range of from 10 to 200 μm, wherein the average layer thickness in areas having a reduced average layer thickness is lower by 7 to 140 μm and is reduced by a range of from 30 to 85% compared to said areas having a non-reduced average layer thickness of the at least one thermoplastic porous absorbing layer, wherein both areas having a reduced average layer thickness and a non-reduced average layer thickness comprise pores which are able to absorb a functional additive, and wherein the areas having a reduced average layer thickness and the areas having a non-reduced average layer thickness show different porosity levels over the inside surface of the casing or may show larger pores in parts of the entire inside surface and smaller pores in other parts of the at least one porous absorbing layer. at least one thermoplastic porous absorbing layer and at least one layer having a barrier effect for water vapour and/or oxygen, wherein said at least one layer having a barrier effect for water vapour and/or oxygen has an average layer thickness in a range of from 5 to 60 μm over the entire surface area, characterized in that said at least one thermoplastic porous absorbing layer comprises as a main component at least one thermoplastic polymer material selected from the group consisting of (co)polyamides and (co)polyolefins, wherein said at least one thermoplastic porous absorbing layer comprises areas having a reduced average layer thickness and areas having a non-reduced average layer thickness, wherein the average layer thickness of said at least one thermoplastic porous absorbing layer in areas having a non-reduced average layer thickness is in a range of from 10 to 200 μm, wherein the average layer thickness in areas having a reduced average layer thickness is lower by 7 to 140 μm and is reduced by a range of from 30 to 85% compared to said areas having a non-reduced average layer thickness of the at least one thermoplastic porous absorbing layer, wherein both areas having a reduced average layer thickness and a non-reduced average layer thickness comprise pores which are able to absorb a functional additive, and wherein the areas having a reduced average layer thickness and the areas having a non-reduced average layer thickness show different porosity levels over the inside surface of the casing or may show larger pores in parts of the entire inside surface and smaller pores in other parts of the at least one porous absorbing layer.