Three-Side Seal vs Side Gusset vs Pillow Pouch vs Quad Seal: Which Bag Format Fits Your Product?
Quick answer
Choose a three-side-seal flat pouch for samples, single servings, sachets and flat products; a pillow (back-seal) pouch for high-speed machine filling of snacks and loose products at low cost; a side-gusset bag when you need more volume in a narrow footprint, such as coffee or larger dry foods; and a quad-seal bag when you want the side-gusset shape with crisp sealed corners, a seamless back panel and better standing. If you are choosing between a flat-bottom bag and a stand-up pouch instead, that comparison is covered in a separate guide.
Quick facts: Custom Flat Bottom Pouches
- Indicative unit price: about US$0.05–0.10 per piece. This is a guide, not a quotation: the final price depends on size, material, print colours, finish and order quantity.
- MOQ: typically from 500 pcs per size and artwork; the confirmed minimum depends on material, print method and features and is stated on the quotation.
- Lead time: Physical samples 5–7 working days after artwork is confirmed; bulk production 20–30 days after sample approval.
- Who makes it: BestPackFactory’s own factory in Longhua District, Shenzhen, China. Free dieline and artwork proof within 24 hours. See real samples and videos.
- Specifications and quote: Custom Flat Bottom Pouches · Request a quote
Format comparison
| Format | Construction | Stands on shelf? | Typical uses | Cost and filling notes |
|---|---|---|---|---|
| Three-side seal (flat pouch) | Two flat panels sealed on three sides; filled through the open fourth side, then sealed | No; lies flat, hangs or sits in a box | Samples, single-serve sachets, jerky, face masks, mylar bags, retort and vacuum packs | Simple and economical; holds relatively little volume for its size |
| Pillow / back-seal pouch | One web folded into a tube with a seal down the back, plus top and bottom end seals | No; rounded, usually displayed lying or hanging | Chips, candy, frozen foods, small snacks, stick-style packs | Usually the lowest film use and cost; commonly run as roll stock on vertical form-fill-seal (VFFS) machines |
| Side-gusset bag | Pillow construction with an inward fold on each side, back seal down the rear panel | Partly; stands best when filled firmly, often leans or lies down | Coffee, tea, flour, rice, pet food, larger dry foods | More volume in a narrow face; often closed with a heat seal, tin tie or added zipper |
| Quad-seal bag | Side-gusset shape with all four vertical corners sealed, usually without a back seam | Yes, better than side gusset; stacks well | Premium coffee, pet food, heavier dry products | Costs more and fills more slowly than pillow or side-gusset bags |
A separate format, the flat-bottom (box-bottom) pouch, adds a sealed rectangular base panel. If that is on your shortlist, read our flat-bottom bag vs stand-up pouch guide rather than this one.
Three-side-seal flat pouches
A three-side-seal pouch is the simplest premade bag: two panels sealed on the left, right and one end, with the remaining end left open for filling. Because it has no gusset, it suits flat or low-volume products and single doses. It gives two clean print panels, prints well edge to edge and packs flat for shipping. A zipper and tear notch can be added for reclosable use. Small sachets and stick packs are close relatives: see the sachet and stick pack dieline for layout and seal widths.
Choose it when the product is flat, the fill is small, the pack goes into a carton or display box, or you need samples and single-serve portions.
Pillow (back-seal) pouches
A pillow pouch is formed from a single printed web wrapped around a forming tube, sealed down the back, then sealed across the top and bottom. This is the familiar crisp-bag shape. It is the format most associated with high-speed automatic packing, and it is commonly bought as printed roll stock rather than premade bags. The back seal can be a fin seal (inner faces sealed together, standing out from the back) or a lap seal (one edge overlapping the other).
Choose it when you fill on a VFFS machine, run high volumes, want the lowest film cost per pack, and do not need the pack to stand up. Keep important artwork away from the back seal area, which interrupts the rear panel.
Side-gusset bags
A side-gusset bag folds inward on both sides, so it opens into a roughly rectangular block when filled. It holds more volume than a flat pouch of the same face width and packs neatly into cartons. Coffee is the classic example, often with a one-way valve and a tin tie or heat seal. The side gussets offer narrow extra print panels, and the back seal runs down the rear.
Choose it when you need more capacity without a wide front, want efficient carton packing, or are packing medium to large fills such as 500 g to several kilograms. Expect the bag to lean unless it is filled firmly.
Quad-seal bags
A quad-seal bag is a side-gusset bag with each of its four vertical corners sealed. The sealed edges hold the shape square, help the bag stand and give a clean back panel without a centre seam. Many buyers choose it for premium coffee and pet food where shelf appearance matters, or for heavier or sharper products where the extra seals add shape and support.
Choose it when you want block-like shelf presence and four printable faces, and the extra cost over a standard side-gusset bag is acceptable.
Decision checklist
- How is it filled? Roll stock on an automatic machine points to pillow or side-gusset formats; hand or semi-automatic filling of premade bags suits three-side-seal, side-gusset and quad-seal bags.
- Does it need to stand on a shelf? If yes, consider quad-seal, stand-up or flat-bottom formats. If it hangs or sits in a box, a flat or pillow pouch is enough.
- How much volume? Small and flat: three-side seal. Medium loose fill: pillow. Large or dense fills in a narrow footprint: side-gusset or quad-seal.
- How many print faces matter? Flat and pillow pouches give front and back; gusseted bags add side panels.
- Is reclosure needed? Zippers are common on flat and stand-up pouches; side-gusset bags are often closed with tin ties or reclosure labels instead.
- What is the cost target? As a general rule, pillow is lowest, then three-side seal and side gusset, with quad seal higher. Confirm with a quotation.
What to send in your RFQ
- Bag format, or the product and fill weight if you want a recommendation
- Dimensions: width, height and gusset depth
- Supply form: premade bags or roll stock, and your filling machine model if relevant
- Features: zipper, tear notch, valve, hang hole, window, tin tie
- Material structure and barrier needs
- Quantity per design and number of designs
Browse the full range under flexible packaging; if your product needs a flat base panel instead, see custom flat-bottom pouches.
Common mistakes
- Choosing a side-gusset bag and expecting it to stand like a stand-up or flat-bottom pouch.
- Ordering premade bags when the filling line needs roll stock, or the reverse.
- Placing text or barcodes across the back seal of a pillow or side-gusset bag.
- Comparing prices between formats without matching volume and features.
- Skipping a filled sample to check how the format looks on the actual shelf.
Frequently asked questions
What is a three-side-seal pouch?
It is a flat pouch made of two panels sealed on three sides and filled through the open fourth side, then sealed. It does not stand on its own and suits samples, single servings and flat products.
What is the difference between a pillow pouch and a side-gusset bag?
Both have a back seal and top and bottom seals. A side-gusset bag also has an inward fold on each side, so it opens into a block shape and holds more volume in a narrower front.
Is a quad-seal bag the same as a side-gusset bag?
It is a side-gusset bag with all four vertical corners sealed. The sealed corners keep the shape square, help it stand and usually remove the centre back seam, at a higher cost.
Which bag format is cheapest?
Pillow pouches made on form-fill-seal machines generally use the least film and cost the least per pack. Final pricing depends on size, material and features and is confirmed in the quotation.
Related pages
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Send your product, fill weight, filling method, preferred format and dimensions, features and quantity. BestPackFactory quotes custom packaging as B2B projects with a site-wide MOQ of 500 PCS. Reach Lisa Wu at lisa@colorprintingpackage.com or WhatsApp +86 158 8653 0985; anything not listed here is confirmed in the quotation.
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