Mylar Bag Sizes: A Simple Guide
Mylar bags are usually sold by fill size, such as 3.5g or 7g, rather than by measurements. That makes it easy to order the right bag, but it can be confusing when you're comparing suppliers. This guide explains what the common sizes mean, gives typical dimensions, and shows how to pick the right one.
Quick answer: for small portions of dry goods, a 3.5g bag (about 130 × 98mm) is the most popular size. It's small enough to keep contents snug and big enough to label clearly.
Mylar bag size chart
| Fill size | Typical bag size (width × height) | Good for |
|---|---|---|
| 1g | around 70 × 100mm | Samples and single portions |
| 3.5g | 98 × 130mm (our bags) | The most common retail size |
| 7g | around 120 × 180mm | Larger single portions |
| 14g | around 150 × 200mm | Bulk portions |
| 28g | around 180 × 260mm | Bulk storage |
Dimensions vary between suppliers, so treat everything except our own 3.5g bag as a rough guide.
How to read mylar bag sizes
Fill size is a guide, not a rule. A "3.5g" label means the bag is designed to hold about 3.5g comfortably. How much actually fits depends on how dense or bulky the contents are.
Dimensions are width × height. Always check whether the height includes the ziplock and tear notch. The space above the seal can't be filled.
Flat and stand-up bags differ. Stand-up bags have a fold-out base (a gusset) that adds capacity without making the bag taller.
How to choose the right size
Leave room at the top. You need a centimetre or two above the contents for the ziplock to close properly and stay airtight.
Match the bag to the contents. Light, bulky items take up more room than dense ones, so if you're unsure, go one size up.
Think about labelling. A bag that's too full makes the writing panel hard to use and the design harder to see.
Our 3.5g mylar bags
Every Nug Packs bag is a 3.5g size, 130 × 98mm, sold in packs of 100. Each bag has:
- an aluminium-lined mylar body that is smell-proof, moisture-resistant and tear-resistant, with a lining that reflects UV light
- a resealable ziplock to keep contents airtight, and heat sealable for an extra-secure seal
- a white panel you can write on with a biro, felt tip or marker pen
- a pre-printed design, with 20+ designs to choose from
UK delivery is free on every order, and we dispatch in plain, unbranded packaging.
Need a different size?
Our standard range is 3.5g bags, available to order now. If you need a different size, we can print our designs at other sizes as a bespoke custom order. Custom orders take considerably longer than stock bags, so get in touch as early as possible and we'll talk you through sizes, quantities and timings.
Contact us about a custom order →
Frequently asked questions
What does 3.5g mean on a mylar bag?
It's the amount the bag is designed to hold. Our 3.5g bags measure 130 × 98mm.
Are mylar bags smell proof?
Yes, when they're sealed properly. The aluminium lining and ziplock together stop odours escaping. Make sure the seal is fully closed along its whole length.
Can I reuse the bags?
The ziplock is resealable, so you can open and close the bags many times.
Can I write on the bags?
Yes. Each bag has a white panel for writing on with a biro, felt tip or marker pen.
Do you sell other sizes?
Our stock bags are 3.5g. We can print other sizes as a bespoke custom order, with a longer lead time. Get in touch to discuss what you need.
How much is delivery?
UK delivery is free on every order. We also ship to Europe.