Types of Sacks (Paper Bags)
The first basic division of paper sack types is into open mouth and valved designs. Each of these may be sub-divided into pasted or sewn closure types and into further subdivisions by the sack body being either gusseted or flat. Further minor variations can also arise from the inclusion of certain other design features.
Open Mouth Sacks
There are four basic open mouth sack designs depending on the type of closure.
A valved sack is closed at both ends during manufacture and includes an entry device for filling purposes in one corner.