The shape of a bag isn’t a matter of fashion but an answer to two questions: what’s inside it, and where it will be placed. Retail requires bags that stand upright and are printed on the front; transportation requires bags that are sturdy and stackable; and powder requires seams that keep the powder contained. This overview describes eight shapes and the best method for creating each one: formed on a vertical form, fill, and seal machine or supplied as a preformed bag.
The Eight Forms
Pillow Case — the basic VFFS design: one back seam plus top and bottom seams; the film forms a cushion around the product. Strong, economical in film use, and the standard for bulk snacks, granules, and powders. The pillowcase is produced directly from the film roll.
3-side seal bag — flat pouch with three seams, flattened and lightweight: sachets for sauce, samples, and single-use doses. The 3-side seal bag is produced on multi-lane sachet machines from the same vertical family.
4-sided seal bag — all four sides sealed, completely enclosed: precise doses of powder and liquid in stick and sachet form, the family behind the stick pack-line; more on that at 4-sided seal bag.
Doypack — the stand-up pouch with a gusseted bottom and display panel: shelf display for coffee, snacks, and premium powdered products. It is delivered preformed and filled at the machine for filling pre-made bags, or from the roll on a machine with a bottom fold. More about the Doypack-his route and his machine.
Block-bottom bag — rectangular box bottom, stands on its own and stacks on a pallet: 500 g to 5 kg of animal feed, pellets, flour. The block-bottom bag requires heavier film and a machine with bottom forming capabilities.
Quad Seal Bag — Four vertical seams keep the bag square and upright: heavy powder that must not sag, often with ventilation in the seams. The Quad Seal Bag combines a standing presentation with a strong presence.
Piping Bag — bag with a spout and screw-on cap for liquids and sauces: honey, sauces, liquid detergent. The spout bag requires a filling station that attaches the spout to the seal.
Bag with a rear seal — resealable strip on the back for reuse after opening: coffee packets, cookies, candy. The bag with a rear seal combines convenience with a permanent gas barrier.
| Form | Is it standing upright? | Typical content | Route |
|---|---|---|---|
| Pillow Case | no | snacks, granules | VFFS from a roll |
| 3-side seal bag | no | sachets, sauce | multi-lane sachet machine |
| 4-sided seal bag | no | sticks, doses | multi-column labeling machine |
| Doypack | yes | coffee, premium | pre-shaped or bottom pleat |
| Block-bottom bag | yes | 500 g to 5 kg | machine with bottom forming |
| Quad Seal Bag | yes | heavy powder | preformed |
| Piping Bag | yes | liquid with a spout | preformed with a spout station |
| Bag with a rear seal | no | resealable, dry | VFFS with strip application |
Form Follows Shelf and Product
Two approaches to the table. The shelf: items on the supermarket shelf stand upright—doypack, block-bottom, quad. The product: anything that flows, runs, or is heavy dictates the seam construction and the film. The full comparison between preformed and roll-fed packaging is in preformed bags or VFFS; you can read the technical side of the story at What is a VFFS?.
Frequently Asked Questions
Q: Can a single machine produce all of these shapes?
No, and that’s the point of the table: the pillow-pack family runs on standard VFFS machines, and the sachets run on multi-lane or similar machines; the stand-up pouches require bottom forming or preformed feed. One line covers one family; the families complement each other as described in Automate the packaging line.
Q: What is the least expensive option per bag?
The pillowcase: one back seam plus top and bottom seams, minimal film waste. Every extra pleat, bottom panel, or closure adds to the amount of film used and the number of machine operations—the math is clear film consumption.
Q: What shape should I choose for powder that needs to stand on its own?
The Quad Seal bag: the four seams keep the sides upright, even when filled with 2 to 3 kg. The block-bottom bag works as well, but with finer powders, the Quad Seal bag creates a sleeker silhouette that sells better in retail.
Related pages
pillowcase | Doypack | block-bottom bag | Quad Seal Bag | spout bag | 3-side seal bag | 4-sided seal bag | bag with a rear seal
Request a technical proposal Please specify the product, bag size, and desired output.
English 
Dutch