Mylar Bag Thickness Guide: What Mil Rating Do You Really Need?

Most home food storage should use bags that are at least 5 mil thick. It’s the sweet spot for durability, puncture resistance, and light protection. But depending on what you’re storing—and how—you may want to go thicker.

Let’s walk through what mil ratings actually mean, when you might want a thinner or thicker bag, and how to avoid some common myths about Mylar quality.

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🧠 Choosing the Right Mil for the Job

Here’s how I generally choose Mylar thickness based on what I’m doing:

Use Case	Suggested Mil Rating
Single-serving meals or snacks	3.5–4 mil
Everyday long-term pantry items (rice, beans, flour)	5 mil
High-risk or rough environments	6–7.5 mil
Bags you plan to reseal or reuse	6+ mil

And whatever you choose, make sure it’s food-safe and paired with the right oxygen absorbers. (Most pre-packaged bundles will match the bag size to the correct cc rating, which helps.)

If you’re unsure about oxygen absorber sizing, I walk through that in more detail in How Long Will Beans Last in Mylar with Oxygen Absorbers?

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🔍 What Does “Mil” Mean?

A mil is a thousandth of an inch. So when someone says a Mylar bag is 5 mil, they’re talking about the combined thickness of its layered material (usually metalized polyester and food-safe plastic). More mils = a tougher, stiffer bag.

Here’s a quick breakdown of the most common thicknesses:

• 3.5 to 4 mil – Good for lightweight, short-term storage like dehydrated herbs or single-use meals.
• 5 mil – The standard for long-term food storage. Balances protection with ease of sealing.
• 7+ mil – Extra thick for high-risk areas (rodents, humidity, rough handling). Also useful for bulk items or reuse.

✅ Tip: If you’re storing beans or rice in bulk, a 5-gallon, 5–7 mil bag inside a food-grade bucket is hard to beat.

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🧱 When to Go Thicker

I tend to stick with 5 mil for most of my food storage. It holds up well during sealing, doesn’t tear when I move it around, and works with most home sealers. That said, there are times when thicker is better:

• You’re storing sharp or dense foods like pasta, beans, or rice in bulk.
• The bags are stored somewhere vulnerable, like a shed or basement where rodents might show up.
• You plan to reuse the bags—thicker ones are far less likely to crease or puncture after opening.

For example, the gusseted Wallaby 1-gallon zipper bags I’ve used are 7.5 mil thick, and they’ve handled everything from chunky dehydrated soup mixes to 30+ lbs of rice without fail.

If you’re not sure how to store these ingredients long-term, my complete walkthrough on How to Store Rice and Beans with Mylar and Oxygen Absorbers is a great place to start.

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🚫 What Mil Rating Doesn’t Guarantee

Here’s the myth I hear all the time: “Thicker Mylar is automatically better.” That’s not always true.

• Thicker bags don’t always seal better—in fact, some cheap impulse sealers can struggle with 7+ mil thickness unless they’re high wattage.
• Pinholes in Mylar don’t mean it’s defective. All Mylar bags—even the best ones—may show tiny light leaks when held up to a flashlight. These don’t necessarily affect the airtight seal, because the aluminum layer is sandwiched between two other layers.
• A thicker bag won’t fix a bad seal. If your impulse sealer leaves a narrow or patchy seam, upgrading to a better sealer will do more for your food than adding another mil of plastic.

If you want to double-check your seals after packing, check out my guide on How to Test if Your Mylar Seal is Airtight (Without Opening It).

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Final Thoughts

The right mil rating depends on your storage goals, but for most of us, 5 mil is the best all-around choice. It’s tough enough for long-term storage, easy to work with, and pairs well with standard sealers.

If you’re storing expensive freeze-dried meals or worried about rodents and handling, go thicker. But don’t fall for the hype that says only 7+ mil bags are worth your time.

Here is a JGP image of the chart, in case you want to save and print it.

Store smart, seal tight, and always label everything. Your future self will thank you.

Thanks for stoppin’ by!

Jelly Grandma