Form-Seal-Fill (FSF) is an innovative in-line bag manufacturing and filling system. Developed by Flextainer, a division of Scholle Packaging, FSF for bag-in-box dramatically changes how bags are produced and supplied.

In a traditional model, film is supplied to a bag manufacturer, who then sends it to a filling center. With the FSF model, film is supplied directly to the filling center, where the FSF system manufactures and fills the bags. By not having to ship to the bag manufacturer, transportation is greatly reduced, allowing for cost savings and lower carbon emissions.