When packing corrosion susceptible products you need corrosion protection to protect against moisture getting to the surfaces of you products. Corrosion protection works in several different ways and it is critical to know which one is best for the parts you are packaging.
Basic corrosion protection can be used for short term packaging and uses products like waxed paper and bitumen paper to reduce the amount of water reaching the packed items. These products are water resistant materials that stop any water getting to the products themselves, however they don't protect very well against airborne moisture as the packaging is very rarely airtight. As a result it will only protect parts in the short term, or protect parts with basic rust protection such as oil coated or painted surfaces.
VCI (volitile corrosion inhibitor) corrosion protection is the next level of corrosion protection and works by evaporating and condensing a corrosion inhibitor. A carrier material, usually paper or polythene, is impregnated with a VCI product which gradually evaporates out of the material and condenses on colder metal parts. This condensed VCI layer protects against moisture reaching the corrodable surfaces of the item. This is very effective because it coates even the tiniest nook and cranny, however it is crucial that the packaging is relatively well sealed or the VCI product can evaporate out of the packaging leaving the parts with no protection. It is because of this that VCI packaging is only recommended for short and medium term protection.
For long term protection against corrosion you need to completely seal your parts within an airtight container which contains enough dessicant inside to remove the moisture in the air within the packaging. This can be achieved with aluminium bags or thick plastic co-extruded with an airproof barrier. Packaging for this level of corrosion protection really needs to be designed specifically for each application, as there are many factors that determine the correct packaging methodology.