The present invention pertains to a process for packaging one or more products, said process comprising the following steps: (i) providing a package having an opening, said package comprising at least one sheet, said sheet comprising the following layers: a layer [layer (L1)] consisting of a composition [composition (C1)] comprising, preferably consisting of, at least one thermoplastic polymer [polymer (T1)], said layer (L1) having two opposite surfaces, wherein one surface comprises one or more grafted functional groups [surface (L1-S1-f)], directly adhered to the surface (L1-S1-f), a layer [layer (L2)] consisting of at least one metal compound [compound (M1)], and optionally, directly adhered to the layer (L2), a layer (L3) consisting of a composition [composition (C3)] comprising, preferably consisting of at least one thermoplastic polymer [polymer (T2)], said polymer (T2) being equal to or different from the polymer (T1); (ii) feeding the package provided in step (i) with one or more products; and (iii) sealing the package provided in step (ii). The present invention also pertains to said package, to a process for the manufacture of said package and to uses of said package in various applications.