Bags or sacks for flour range in size and material, from large bulk bags, in cotton or woven polypropylene, to smaller consumer packaging, often made of paper.
These printed cotton bags were sometimes viewed as collectables; other times the flour sack fabric was repurposed into a variety of household items.
Some include a layer of plastic film for barrier properties and insect control.
Packaging engineers and food scientists need to understand the properties of the particular flour, intended handling and logistics systems, and desired shelf life.
[5][6] When insect infestation is noted, one method of stopping further growth is to freeze the sacks of flour for several days.