Coffee bags with valve is the recognized format for coffee packaging today. It is the tried and true "coffee bag", and offers the most selection within our coffee packaging line, with many colors and sizes available.
The name comes from the side folds or "gussets" on the bag. It is also widely used in other markets such as, pet food, powders goods, teas and other specialty food products.

Fujin coffee bags with valve one-way degassing valves are designed to allow pressure to be released from an airtight package while not allowing external atmosphere (i.e. air with 20.9% O2) to enter the package. 

The coffee bag gussets expand when the package is filled with product, and the weight of the product usually holds the bag upright. This coffee sack package format has two long faces, or panels, on the front and the back for product branding.