Mylar bag thickness, answered fast
For most food and retail packaging, a 5 mil mylar bag is the practical default: it resists punctures, holds a strong heat seal, and protects flavor for long storage. Choose 3 mil for lightweight or short-term goods, and step up to 7 mil for sharp-edged, heavy, or long-term bulk contents.
Thickness in mylar packaging is measured in mils, where one mil equals one-thousandth of an inch (0.001"). It describes the total wall of the film, which is usually a multi-layer foil laminate rather than a single sheet. Thicker film means more puncture resistance, a sturdier seal, and a better barrier against oxygen, moisture, and light.
The tradeoff is cost and flexibility. Thicker bags use more material and cost more per unit, and very thick film can feel stiff for small pouches. The goal isn't the thickest bag possible, it's matching the thickness to your product weight, storage time, and how the bag gets handled in shipping and on the shelf.
According to the standard conversion, one mil equals 25.4 microns, so a 5 mil bag is about 127 microns. If you know your product's weight, edges, and shelf life, you can pick a thickness with confidence.
Mil vs micron vs gauge, explained
These three units all measure film thickness, they just use different scales, which is why spec sheets can get confusing. Here is how they line up.
- Mil: one mil = 0.001 inch. The common US unit for mylar and flexible packaging.
- Micron (µm): one mil = 25.4 microns. Common in metric spec sheets.
- Gauge: 100 gauge = 1 mil. So a 500-gauge film is 5 mil.
A quick reference: 3 mil is roughly 76 microns (300 gauge), 5 mil is about 127 microns (500 gauge), and 7 mil is close to 178 microns (700 gauge). When a supplier quotes microns, divide by 25.4 to get mils. When they quote gauge, divide by 100.
3 mil vs 5 mil vs 7 mil: comparison table
Here's how the three most common mylar thicknesses compare across the factors that matter for a buying decision.
| Thickness | Approx. metric | Best use | Durability | Cost tradeoff |
|---|---|---|---|---|
| 3 mil | ~76 µm / 300 gauge | Snacks, dry mixes, single-serve, sampling, short-term storage | Light: flexible, thinner wall, easier to tear or puncture | Lowest per-unit cost, best for high-volume lightweight items |
| 5 mil | ~127 µm / 500 gauge | Coffee, whole foods, retail resale, most general-purpose use | Strong: solid puncture resistance and reliable heat seals | Mid cost, the usual best value for food and retail |
| 7 mil | ~178 µm / 700 gauge | Bulk grains, heavy or sharp contents, long-term emergency storage | Heavy-duty: highest puncture resistance and seal integrity | Highest per-unit cost, justified for weight and long shelf life |
Which thickness for coffee, food, powders, and bulk
The right thickness depends on weight, edge sharpness, and how long the product sits sealed. Here's a use-case breakdown.
Coffee
Use 5 mil for most roasted coffee. It gives a strong barrier to keep beans fresh, holds a clean seal around a one-way degassing valve, and stands up to retail handling. For single-serve or sample sachets, 3 mil keeps cost down. Our stand-up mylar pouches are a common choice for shelf-ready coffee.
Food and dry goods
For everyday food like snacks, dried fruit, jerky, and dry mixes, 3 to 5 mil covers most needs. Go 5 mil when the product is dense or the bag will be shipped and restacked. For a foil laminate built around food storage, see custom mylar food storage bags.
Powders
Powders such as protein, drink mixes, and spices seal well at 5 mil, which resists the fine-particle stress on seams and holds a durable seal. Fine powders can migrate into a weak seal, so a thicker wall and a full-width heat seal help. Explore custom printed mylar bags for branded powder pouches.
Bulk and long-term storage
For bulk grains, beans, rice, and long-term emergency food, choose 5 to 7 mil. Heavy contents and sharp grain edges reward the extra wall, and a thicker bag pairs well with oxygen absorbers for multi-year storage. Size your absorbers with our oxygen absorber calculator, and use the mylar bag size finder to match volume to bag. For a stronger seal on bulk, a vacuum-seal mylar bag adds another layer of protection.
How Teal builds mylar bags to spec
Teal is a US-based packaging supplier with fulfillment in West Chicago, IL. We build mylar bags from multi-layer foil laminate, quoted to your exact thickness, size, and finish. Standard MOQ starts from 50 units, with pricing from $0.44 per unit on bulk orders, quoted to spec. Every order includes free dieline design, full-color print, two revision rounds, and free US shipping. Production runs from about 7 business days after proof approval (complex or high-volume jobs can run longer), plus 2 to 5 business days for US delivery. Recyclable options are available by specification. Browse custom mylar bags to start.
Frequently Asked Questions
What thickness of mylar bag is best for long-term food storage?
For long-term storage of bulk dry goods, 5 to 7 mil is the common choice. The thicker wall resists punctures from sharp contents like grains and pairs well with oxygen absorbers for multi-year shelf life. Match the absorber size to your bag volume for best results.
How thick is a 5 mil mylar bag in microns?
A 5 mil mylar bag is about 127 microns, since one mil equals 25.4 microns. In gauge, that's 500 gauge, because 100 gauge equals 1 mil. To convert any micron value to mils, divide by 25.4.
Is a thicker mylar bag always better?
Not always. Thicker film costs more per unit and can feel stiff on small pouches, so it's best matched to product weight, edge sharpness, and storage time. For lightweight, short-term goods, 3 mil often does the job at a lower price. The right thickness is the one that fits your use case.
What's the difference between mil and gauge?
Both measure film thickness. One mil equals 0.001 inch, while gauge is a finer scale where 100 gauge equals 1 mil. So a 300-gauge film is 3 mil and a 700-gauge film is 7 mil. Suppliers may quote either, so convert by dividing gauge by 100.
Can I get a custom thickness printed with my brand?
Yes. Teal quotes mylar bags to your exact thickness and size with full-color printing, free dieline design, and two revision rounds. MOQ starts from 50 units, and you can request a sample kit (free, with a $19.99 shipping charge credited to your order) to check the material before committing.
Ready to spec the right thickness for your product? Request a quote and our team will help you match mil, size, and finish to your goods, or order a sample kit to feel the material first.
Ben Russell
Ben is a Senior Packaging Strategist and writer at Teal Packaging, covering packaging materials, design strategy, and practical branding insights.
