01What a sachet is (both meanings)
Merriam-Webster gives two senses of "sachet": "a small bag or packet", and a small bag of perfumed powder or potpourri for scenting clothes and linens.
In packaging, a sachet is a single-use packet of laminated film sealed on every open edge: a ketchup packet, a face cream sample, a dose of electrolyte powder. A stick pack is a sachet shaped like a narrow tube, torn open at one end to pour.
02The three formats
| Format | How it's built | What it suits |
|---|---|---|
| 3-side seal sachet | One web of film folded in half lengthwise; the fold is one edge and the other three are sealed | Flat packets of powder, liquid or cream |
| 4-side seal sachet | Two webs, one on each face, sealed along all four edges | Packets sealed on every edge |
| Stick pack | One web wrapped around a forming tube, sealed down its length, then sealed and cut at each end | Single servings you pour, like drink mixes and supplements |
On a horizontal pouch machine, a plow folds the web in half lengthwise and heated bars add side seals at intervals (Cloud Corp patent US 5,699,653). A four-side seal machine seals the product between two webs, along both long edges and each end (patent EP 0516487).
Stick packs can save film. Aaron Brody wrote in Packaging Strategies (2007) that a stick pack "requires up to 45 percent less material than traditional square or rectangular packages". That is an upper figure; ask your film supplier for a comparison of both formats at your fill.
03How they're made: roll stock and form-fill-seal
Form-fill-seal packs don't come empty. You buy printed film on a roll (roll stock), and a form-fill-seal machine forms, fills, seals and cuts the packs in one pass. Viking Masek describes its stick pack machines this way:
- the wide roll is slit into strips, one per lane;
- each strip goes over a collar and is folded around a forming tube;
- a vertical seal bar makes the lengthwise seal;
- a filler (a volumetric filler, an auger filler or a liquid pump) doses the product into the tube;
- a horizontal seal makes the top of one stick and the bottom of the next, and the line can notch the seal for tearing before cutting the sticks apart;
- the sticks can then go to checkweighers, x-ray and carton or case packers.
The lengthwise seal is a fin or a lap. A fin seal joins inside to inside; a lap seal joins inside to outside, so the outside layer has to seal too (Constantia Flexibles). Viking Masek says a lap seal uses less material. Constantia also notes that most stick pack machines run at a low sealing temperature, so the film needs a low-temperature sealant. Settle the seal type with the co-packer before you print.
04Films and barrier
Sachet film is a laminate: a print layer outside, often a barrier layer, and a heat-seal layer inside. Constantia Flexibles, a film maker, lists these for its own products:
- Stick packs: PET/aluminum/PE, PET/metallized PET/PE, and PP/PE white. It calls the aluminum versions high barrier.
- Retail sachets for personal care: paper/aluminum/PE, PET/aluminum/PE, PET/metallized PET/PE, OPP/metallized OPP/PE, and a mono-PE laminate it says is designed for recycling.
PET is polyester film, OPP is oriented polypropylene and PE is polyethylene. Ask your converter to write the structure outside to inside and say which layer is the sealant.
Barrier matters a lot for powders. A 2024 review in Foods and Raw Materials found that "due to their high hygroscopicity, powders tend to absorb moisture from the environment and become prone to caking", and that aluminum laminated packaging protected fruit powders well in storage. For a long shelf life on a moisture-sensitive mix, ask for a foil or high-barrier structure and test it with your product.
Ask for numbers, measured the standard way:
- Water vapor transmission rate (WVTR) by ASTM F1249.
- Oxygen transmission rate (OTR) by ASTM D3985.
- Seal strength by ASTM F88.
- Gross leaks by ASTM D3078 (bubble emission), which ASTM says may miss small leaks.
05Labeling a pack this small
For US food, 21 CFR 101.7 sets the net quantity rules, small packs included:
- State it by weight for a powder or other solid, semisolid or viscous food, and by fluid measure for a liquid.
- Under 4 pounds or 1 gallon, state it in ounces. A metric statement may appear as well.
- On a principal display panel of 5 square inches or less, the "bottom 30 percent" placement rule doesn't apply, but the numbers must still be at least one-sixteenth of an inch tall.
- It must be accurate. Reasonable variations from moisture and unavoidable manufacturing deviations are recognized, but they "shall not be unreasonably large." So put fill tolerance in your spec.
- If each stick is labeled to be sold on its own and you sell a carton of identical sticks, the carton must state the number of units, the quantity of each, and the total.
Nutrition labels have small-package rules too. A food in a package with less than 12 square inches of total labeling surface is exempt from nutrition labeling if the label carries no nutrition claims, but it must give an address or phone number for the information (21 CFR 101.9(j)(13)). Dietary supplements still need Supplement Facts: under 12 square inches the type can be as small as 4.5 point, and smaller on an inner pack that can't fit it when the outer carton carries a compliant label and isn't separated at retail (21 CFR 101.36(i)(2)). Cosmetic samples follow 21 CFR 701.13, which also uses weight for creams and fluid measure for liquids.
This isn't legal advice: have a labeling consultant review artwork before you print.
06Food contact: what to ask for
No film is "FDA approved." What you want from a supplier is a statement that each layer is made of materials that comply with the relevant FDA regulations for your intended use, such as:
- 21 CFR 174.5, the general rules: substances in food-contact articles must be used under good manufacturing practice and be of a purity suitable for the use, and food contact substances can also be cleared through an effective Food Contact Notification.
- 21 CFR 177.1520 for olefin polymers, which include polyethylene and polypropylene layers.
- 21 CFR 177.1630 for polyethylene phthalate (PET) films.
- 21 CFR 175.105 for the laminating adhesive. It allows adhesives separated from the food by a functional barrier, or within limits that depend on whether the food is dry, fatty or aqueous.
Ask for a letter of guaranty that names those sections, your food type and the use conditions.
07When to pick which, and what drives the order
Decision rule:
- Stick pack for one serving of a free-flowing powder or thin liquid that gets poured.
- 3-side or 4-side seal sachet for creams, gels, sauces and samples that get squeezed out, or when you need a wider label face.
- A pouch or bag once you're past a few servings: see stand-up pouches and mylar bags.
If you don't own a form-fill-seal line, you buy roll stock from a film converter and have a co-packer fill it, or the co-packer sources the film. That's two minimums to ask about, and they may not match. Ask each:
- What is your minimum per SKU (per flavor or artwork), for film and for filling?
- How many meters of film does each changeover waste?
- What fill tolerance do you hold, and do you checkweigh every stick?
- Which seal types and widths can your line run?
- Do you carton the sticks, and in what count per carton and per case?
Read our guide to what MOQ means before you negotiate. Brody noted that multipacks often go into paperboard cartons; see folding cartons for that layer. The Vault lists packaging suppliers with contacts on our packaging manufacturer list.
08Before you sign off
- Get the roll specs (web width, core, roll diameter, unwind direction) from the co-packer before the film is printed. A roll that doesn't fit their line is scrap.
- Run your own product on the real film before you order a full roll.
- Get label copy reviewed before print files go out.
09How to spec it with a supplier
Send the same spec to every film supplier and co-packer.
| No. | Field | What to write |
|---|---|---|
| 01 | Format | 3-side seal, 4-side seal or stick pack; finished width x length in mm, with tolerance |
| 02 | Fill | Product type (powder, liquid, cream), target fill weight or volume, allowed tolerance |
| 03 | Film structure | Each layer outside to inside, with thickness in microns, and the sealant |
| 04 | Seal | Fin or lap for sticks; seal width; ask for ASTM F88 seal strength results |
| 05 | Barrier | Target WVTR and OTR with test method (ASTM F1249, D3985) and conditions |
| 06 | Opening | Tear notch or laser score position; easy-open test on samples |
| 07 | Number of colors, Pantone references, print method, eye mark for the machine | |
| 08 | Roll | Web width, repeat length, core size, maximum roll diameter, unwind direction (get these from the co-packer) |
| 09 | Compliance | Letter of guaranty naming 21 CFR 174 to 178 sections for each layer and the adhesive |
| 10 | Packing | Units per carton, cartons per case, case marks |
10FAQ
Q01What is a sachet?
A small bag or packet. In packaging, a sealed single-dose packet of laminated film; at home, a scented bag for drawers.
Q02What is the difference between a stick pack and a sachet?
A stick pack is a long, narrow tube sealed down its length and at both ends, made for pouring. A sachet is a flatter packet sealed on three or four edges, better for squeezing out creams and sauces.
Q03What are sachets made of?
Laminated film: an outer layer such as PET, paper or OPP, often a foil or metallized barrier, and a polyethylene layer. Mono-PE laminates exist for recycling.
Q04Are sachets recyclable?
Many of the common structures combine different materials, such as film and foil. You can call a package "recyclable" without qualification only if the FTC Green Guides test is met (16 CFR 260.12), so check before you print any claim.
Q05Can I buy empty sachets or stick packs?
Not for form-fill-seal packs: the machine forms them from roll stock as it fills, so you buy printed film and have a co-packer (or your own line) fill it.