Sachet Packaging Design Tips: Tear Notch, Round Corner, Side Gusset & Resealable Zippers

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Avocado chips in a green pillow pack snack sachet

If you sell single-serve snacks, drink powders, sauces, coffee, supplement samples, wet wipes, shampoo testers or pet treats, sachet packaging is probably already on your shortlist. The format is compact, cheap to ship and easy for customers to grab on the go. 

Most buyers know they want a sachet or flat pouch. What’s tricky is the add-ons — tear notch, round corner, side gusset, resealable zipper — and which ones actually matter for their product.
Pick the wrong combination and you either pay for features your product doesn’t need, or ship a pack that’s awkward to open or store.

Here, we’ll show you sachet features, explain what each one does, and guide you on how to match them to your product. DigiPac makes flat pouches in two base formats — Pillow Pack (Center Seal) and 3-Side Seal — and the right starting point is choosing between those before you touch a single add-on.

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Why Sachet Packaging Design Details Matter

Small add-ons change how a sachet opens, feels in the hand and performs on the shelf — and the right one depends entirely on your product. A tear notch is about opening. A round corner is about handling and looks. A side gusset is about volume. A resealable zipper is about reuse.

The right feature depends on product type, filling format and how the customer uses the pack.
Some features change how the pack opens, some change how it’s handled, and some change its structure.
Adding everything is rarely the answer. For example, a single-use ketchup sachet doesn’t need a zipper, and a coffee refill pack doesn’t need rounded corners.

Start by Choosing the Right Flat Pouch Type

Before you choose any feature, choose the base format. A flat pouch is a compact, lay-flat package, and at DigiPac, we offer two: Pillow Pack (Center Seal) and 3-Side Seal. This choice decides which add-ons are even available to you, so it’s the real starting point for any sachet design.

Six colorful snack bags in printed pillow pack packaging

Pillow Pack (Center Seal)

A Pillow Pack, or Center Seal pouch, is back-sealed with a fin seam down the back and closures at the top and bottom. It’s the workhorse format for dry, free-flowing products.

Best for dry goods, powders and single-serve snacks, such as sugar sticks, coffee premix and snack portions.
Runs on manual or automated filling lines, so it scales from short runs to high-volume production.
A side gusset can be added to this format when you need more capacity than a flat sachet allows.

3-Side Seal

A 3-Side Seal pouch is sealed on three edges with one open end for filling. It’s the slim, clean-faced format you see on cosmetic testers and sauce sachets.

Suits liquids, powders and sample packs.
Sleek and slim, so it stores flat and displays cleanly on a shelf or in a hanging strip.
Compatible add-ons include a resealable zipper, a spout and a custom die-cut shape.
Colorful FurryTail stick pack sachet packaging for single-serve pet treats

What Each Sachet Feature Actually Does

The four most common sachet add-ons each solve a different problem: a tear notch helps opening, a round corner improves handling and looks, a side gusset adds volume, and a resealable zipper allows reuse. Here’s how to tell them apart.

Tear notch
Round Corner
Side Gusset
Resealable Zipper

Tear Notch

Hand holding a pillow pack snack sachet with a tear notch for easy opening

A tear notch is a small V-shaped or semi-circular cut on the edge of a pouch that gives the customer a clean, designated point to start tearing. It is the single most useful opening feature for small sachets.

The notch sits just below the seal. It uses tiny cuts in the film to guide the tear straight across the pack, so you don't need scissors and won't get a messy rip.
It is mainly there to make the pack easier to open. That helps a lot on single-use sachets, sample packs and small pouches.
It also works as a safety sign. This means if the notch is still whole, the pack has not been opened yet.
On packs with a zipper, a clean tear keeps the zipper in one piece. It’s recommended to put the notch about 6 mm (0.25″) above the zipper.

Round Corner

Blueberry pancake mix in a resealable stand-up pouch with round corners

A round corner replaces the sharp 90-degree corners of a pouch with a smooth, curved edge. It is mainly about comfort and presentation rather than structure.

Softer edges, more comfortable handling and a cleaner, more premium look.
Useful for sample packs, personal-care sachets and any consumer-facing format the customer holds.
More about feel and finish than function — it won’t add capacity or change how the pack opens.

Side Gusset

Row of colorful side gusset pouches for whole bean coffee

A side gusset is a folded panel on each side of the pouch that expands as the pack is filled. Its job is extra capacity.

The folds open out to hold more product. Side gusset panels increase filling volume and let the pack take a fuller, box-like shape.
On DigiPac’s flat pouches, the side gusset is offered on the Center Seal / Pillow Pack format.
Useful when the pack needs more room than a very flat sachet — bulkier powders, granola or larger portions.
Stays compact when empty, then expands once filled.

Resealable Zipper

Three wellness pouches with resealable zippers in pink, orange and yellow

A resealable zipper is an interlocking closure that lets the customer open and reclose the pouch repeatedly. It exists for products that aren’t finished in one sitting.

Mainly for repeated opening and closing, keeping the contents fresh between uses.
For our flat pouches, the zipper is offered in the 3-Side Seal format.
Useful when the product is meant to last — multi-serve snacks, supplement powders or pet treats.
Pairs naturally with a tear notch: tear once to open, then zip to keep

The four most common sachet add-ons each solve a different problem: a tear notch helps opening, a round corner improves handling and looks, a side gusset adds volume, and a resealable zipper allows reuse. Here’s how to tell them apart.

Tear notch
Round Corner
Side Gusset
Resealable Zipper

Tear Notch

Hand holding a pillow pack snack sachet with a tear notch for easy opening

A tear notch is a small V-shaped or semi-circular cut on the edge of a pouch that gives the customer a clean, designated point to start tearing. It is the single most useful opening feature for small sachets.

The notch sits just below the seal. It uses tiny cuts in the film to guide the tear straight across the pack, so you don't need scissors and won't get a messy rip.
It is mainly there to make the pack easier to open. That helps a lot on single-use sachets, sample packs and small pouches.
It also works as a safety sign. This means if the notch is still whole, the pack has not been opened yet.
On packs with a zipper, a clean tear keeps the zipper in one piece. It’s recommended to put the notch about 6 mm (0.25″) above the zipper.

Round Corner

Blueberry pancake mix in a resealable stand-up pouch with round corners

A round corner replaces the sharp 90-degree corners of a pouch with a smooth, curved edge. It is mainly about comfort and presentation rather than structure.

Softer edges, more comfortable handling and a cleaner, more premium look.
Useful for sample packs, personal-care sachets and any consumer-facing format the customer holds.
More about feel and finish than function — it won’t add capacity or change how the pack opens.

Side Gusset

Row of colorful side gusset pouches for whole bean coffee

A side gusset is a folded panel on each side of the pouch that expands as the pack is filled. Its job is extra capacity.

The folds open out to hold more product. Side gusset panels increase filling volume and let the pack take a fuller, box-like shape.
On DigiPac’s flat pouches, the side gusset is offered on the Center Seal / Pillow Pack format.
Useful when the pack needs more room than a very flat sachet — bulkier powders, granola or larger portions.
Stays compact when empty, then expands once filled.

Resealable Zipper

Three wellness pouches with resealable zippers in pink, orange and yellow

A resealable zipper is an interlocking closure that lets the customer open and reclose the pouch repeatedly. It exists for products that aren’t finished in one sitting.

Mainly for repeated opening and closing, keeping the contents fresh between uses.
For our flat pouches, the zipper is offered in the 3-Side Seal format.
Useful when the product is meant to last — multi-serve snacks, supplement powders or pet treats.
Pairs naturally with a tear notch: tear once to open, then zip to keep

Which Feature Fits Which Product Use Case?

As a rule, dry-fill products start with a Pillow Pack, while samples and multi-use packs start with a 3-Side Seal. Then you layer on the one or two features that match how the product is used.

Product Type Best Pouch Direction Best Features
Dry-fill products (sugar, premix, snacks) Pillow Pack (Center Seal) Side gusset if extra volume is needed
Sample / single-use sachets 3-Side Seal Tear notch
Consumer-facing sachets 3-Side Seal Round corner + tear notch
Multi-use small packs 3-Side Seal Resealable zipper
3-Side Seal cosmetic sample sachet packaging, a common format for beauty and skincare testers

For inspiration, look at how familiar brands handle the format. NESCAFÉ 3 in 1 is sold in single-serve coffee sachets and sticks; stick-pack hydration mixes show how a slim single-serve pack travels well; and beauty brands lean on 3-side-seal sachets for skincare and cosmetic testers. The base format and one well-chosen feature do most of the work.

How DigiPac Can Help

At DigiPac, we make custom flat pouches in both Pillow Pack (Center Seal) and 3-Side Seal formats, and helps you match the right add-ons for each.

Both base formats under one roof: Center Seal for dry-fill products, 3-Side Seal for samples and reusable packs.
Guidance on which add-ons pair with which format: side gusset with Center Seal; resealable zipper, spout and custom die-cut with 3-Side Seal.
Sustainable material choices, including recyclable, compostable and mono-material structures.
Support from design through to delivery, so the artwork, format and features all line up before production.

Conclusion

Good sachet packaging design starts with the base format, not the features. Choose Pillow Pack (Center Seal) for dry-fill products or 3-Side Seal for samples and reusable packs, then add only the features that improve opening (tear notch), handling and looks (round corner), volume (side gusset) or reuse (resealable zipper). Skip the rest — the cleanest pack is the one with exactly the features your product needs and nothing it doesn’t.

Not sure which flat pouch type and sachet features fit your product? Talk to DigiPac and we’ll help you choose the right base format and add-ons before you commit to a run.

Request Quotation

Frequently Asked Questions

What is sachet packaging?

Sachet packaging is a small, flat, single-serve or single-use pouch used for products such as coffee, sauces, powders, cosmetic samples and wet wipes. It is compact, lightweight and inexpensive to ship, which makes it popular for on-the-go products and free samples. Most sachets are made as flat pouches in either a Pillow Pack (Center Seal) or 3-Side Seal format.

What is the difference between a Pillow Pack and a 3-Side Seal pouch?

A Pillow Pack (Center Seal) is sealed along the back and across the top and bottom. It suits dry goods, powders and snacks. A 3-Side Seal pouch is sealed on three edges with one open end for filling, and suits liquids, powders and sample packs. The format you choose also decides which add-ons you can use.

Can a sachet have both a tear notch and a resealable zipper?

Yes. On a resealable 3-Side Seal pouch the two features work together: the tear notch gives a clean opening point, and the zipper lets the customer reclose the pack between uses. A tear notch placed just above the zipper keeps the closure intact, so the pouch reseals reliably after the first open.

Which sachet feature is best for sample packs?

For single-use sample packs, a tear notch is the most valuable feature because it makes the sachet easy to open without scissors. A round corner is a useful addition for consumer-facing samples, giving a softer feel and a more premium look. Samples are usually built on the slim 3-Side Seal format.

Get in Touch

Looking for eco-friendly packaging that reflects your brand?

Lot 26 Rawang Integrated Industrial Park,
48000 Rawang,
Selangor Darul Ehsan,
Malaysia.

+6012 308 8928

info@digipac.com.my

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