A gusset on a bag is a folded panel built into the side or bottom that lets the bag expand. When the bag is empty, the gusset folds flat. When you fill it, the gusset opens up and gives the bag depth.
If you’ve ever opened a paper shopping bag and watched it go from flat to boxy, you’ve used a gusset. That extra room is why gusseted bags hold more, stand up on their own, and fit bulky or square items better than flat bags.
Gusset Meaning
The word comes from the French gousset, a piece of armor that covered the gap under the arm. In sewing, a gusset is still an extra panel added to give clothing room to move, such as under a sleeve.
In packaging, the idea is the same: a gusset adds a third dimension. A flat bag has a width and a length. A gusseted bag has a width, a length and a depth.
- Gusset (noun): the folded panel itself.
- Gusseted (adjective): a bag that has one, as in “a gusseted poly bag.”
Why Bags Have Gussets
- More capacity without a bigger footprint. A gusseted bag holds more than a flat bag of the same width, and it still folds flat for storage and shipping.
- It stands up. Bottom and flat-bottom gussets give the bag a base, which matters on store shelves, on counters and in displays.
- A better fit for boxy products. Shoe boxes, take-out containers, apparel and stacked items sit naturally in a gusseted bag instead of stretching a flat one.
- Less wasted material. You get the volume you need from a smaller bag, instead of sizing up to a larger flat bag that’s mostly empty space.
Types of Gussets
| Type | Where the fold is | What it’s good for | Common examples |
|---|---|---|---|
| Side gusset | Both sides of the bag | Adds depth while keeping a slim, upright shape | Paper shopping bags, gusseted poly bags, cello bags |
| Bottom gusset | The base of the bag | Lets the bag stand up on its own | Stand-up pouches, snack and candy bags |
| Flat bottom (block bottom) | Sides and bottom together, forming a rectangular base | The most stable shape; sits like a box | SOS paper bags, grocery and retail bags |
| Quad seal | Side gussets with a sealed seam at all four corners | Holds a crisp, boxy shape when full | Coffee, pet food, bulk dry goods |
A bag can combine types. Most paper shopping bags, for example, have side gussets and a flat bottom.
How to Read Gusseted Bag Sizes
Gusseted bags list three measurements instead of two.
- Paper shopping bags are listed as Width x Depth x Height. The depth is the side gusset. For example, a 5-1/2W x 3-1/4D x 13H brown kraft paper bag is 5-1/2″ across the front, 3-1/4″ deep when the gusset is opened, and 13″ tall.
- Gusseted poly bags are listed as Width x Gusset x Length. For example, a 24W x 20G x 48L gusseted poly bag is 24″ wide, has a 20″ gusset, and is 48″ long.
To measure a gusseted bag yourself: lay it flat and measure the front panel from side to side, not counting the folds (width). Open the gusset fully and measure its depth. Then measure from the bottom to the opening (height or length).
Gusseted Bag vs. Flat Bag: Which Do You Need?
Choose a gusseted bag when your product is thick, boxy or heavy, when the bag needs to stand up, or when you’re packing several items together. Choose a flat bag for thin items like documents, flat-folded apparel or small parts, where extra depth would only add bulk.
A quick test: if the item is more than about an inch thick, a gusset will usually give a cleaner fit than sizing up to a bigger flat bag.
Frequently Asked Questions
What does gusseted mean?
Gusseted means a bag has a gusset: a folded panel on the side or bottom that lets it expand.
What is a gusset on a paper bag?
It’s the folded side panel that opens up to give the bag depth. On a paper shopping bag, it’s the “D” in a W x D x H size.
What’s the difference between a side gusset and a bottom gusset?
A side gusset adds depth along the sides of the bag. A bottom gusset adds a base so the bag can stand up. Many bags have both.
Are gusseted bags more expensive?
They can cost a little more than flat bags of the same width because they use more material and an extra folding step. They often save money overall, because you can use a smaller bag that fits the product better.
Find the Right Gusseted Bag
Action Packaging carries gusseted poly bags, gusseted poly bags on rolls, and paper shopping bags and Eurototes in hundreds of sizes, plus custom printed bags with your logo. Not sure which size you need? Request a custom quote or call (888) 595-4626 and our team will help you find the right fit.