Mailing envelopes and small packages may receive as many as 27 handlings during shipment with the maximum drop height of 1.2 metres (3.9 ft).
[1] The contents of the mailing envelopes often need protection from shock and vibration damage.
Cushioning or padding can be built into the mailing envelope to help protect the contents.
[2][3][4][5] The exterior envelope can be made of a heavy paper, paperboard, corrugated fiberboard or plastic film.
The study recommended use of future products with lower mass and which use renewable resources.