Disclosed is a system for, or method of, packaging a product within a packaging bag, wherein the packaging bag includes an inner liner and an outer liner. The method including the steps of marking the inner liner with a first marking unit, filling the bag with the product, and subsequently marking the outer liner with a second marking unit. The markings may be machine readable and/or randomly generated and stored in a database. The system may further include a machine reader, which is capable of accessing the database, and which is capable of reading the markings on the inner liner and/or the outer liner, to thus determine if an outer liner subsequently removed from an inner liner is/was the same outer liner associated with the same inner liner, at the time when the bag was filled and/or packaged.