For most clothing, 60 µm co-ex mailing bags are a safe default. 50 µm suits light, soft items such as accessories and single garments; 70 µm or more suits heavier orders, sharp corners and bulky items. Each 10 µm adds roughly a fifth to the film weight of a 50 µm bag, so pick the thinnest film that survives your own drop and pack test.
A micron (µm) is one thousandth of a millimetre. Mailing bag thickness is the thickness of a single wall of film, so a 60 µm bag is made of a film 0.06 mm thick, and the two sides of the bag together are 0.12 mm.
European suppliers quote microns. UK buyers often think in gauge, US buyers in mil. The conversions are simple:
| Microns (µm) | UK gauge (1 µm = 4 gauge) | US mil (1 mil = 25.4 µm) |
|---|---|---|
| 50 | 200 | ≈ 2.0 |
| 60 | 240 | ≈ 2.4 |
| 70 | 280 | ≈ 2.8 |
| 80 | 320 | ≈ 3.1 |
| 100 | 400 | ≈ 3.9 |
Our micron, gauge and mil converter does the arithmetic for any value.
Think about three things: how heavy the order is, whether it has hard or sharp edges, and how rough the journey is (a domestic next-day service is gentler than a cross-border route with several hubs).
| Thickness | Typical use | Watch out for |
|---|---|---|
| 50 µm | Accessories, scarves, single light garments, soft items under about 1 kg | Sharp corners, buckles, boxed items |
| 60 µm | Most clothing: T-shirts, knitwear, jeans, two or three garments | Very heavy multi-item orders |
| 70–80 µm | Heavier orders, shoes in boxes, items with hard edges | You pay for film you may not need on light items |
| up to 100 µm | Bulky textiles, bedding, heavy or awkward items | Weight and stiffness; consider whether a different pack suits better |
These are starting points, not rules. A 50 µm bag that survives your tests is better than a 70 µm bag chosen "to be safe", because every extra micron costs material and weight on every order.
Film weight rises in direct proportion to thickness. For polyethylene you can estimate it as:
weight (g) = film area (m²) × thickness (µm) × 0.92
0.92 g/cm³ is the typical density of low-density polyethylene (our main raw material's data sheet gives 0.920 g/cm³). A bag uses two walls plus the flap. For a 320 × 420 mm bag with a 50 mm flap:
Illustrative calculation. Co-ex blends, adhesive strip and print change the real figure slightly.
Across 10,000 orders, moving from 70 µm to 60 µm in this size saves around 26 kg of plastic. That matters wherever your packaging fees or shipping rates depend on weight. Our mailing bag weight calculator works this out for any size.
No. Two bags of the same thickness can behave very differently:
You may have heard that plastic bags under 50 microns are banned or charged in the EU. That line comes from the EU rules on plastic carrier bags: Directive (EU) 2015/720 defined lightweight plastic carrier bags as those with a wall thickness below 50 microns, and defined plastic carrier bags as bags supplied to consumers at the point of sale. National rules built on it, such as charges or bans on lightweight shopping bags, target carrier bags handed out in shops, not mailing bags.
For mailing bags, the more relevant EU rule is the Packaging and Packaging Waste Regulation (PPWR), which applies from 12 August 2026. It requires packaging weight and volume to be reduced to the minimum necessary for safety and functionality. In practice that points the same way as the test above: the right thickness is the thinnest one that protects your goods. Read our PPWR guide for the wider picture.
We produce co-ex mailing bags in our own factory in Istanbul, usually between 50 and 70 µm, and up to 100 µm on request; a 70% recycled-content option is available. Nothing in the range is fixed: other thicknesses and sizes are made to order. See the thickness guide on our mailing bag page, or request the free sample kit and run the test with your own products.
There is no single correct thickness. As a starting point, 50 µm for light accessories, 60 µm for most clothing, 70–80 µm for heavier or sharp-cornered items and up to 100 µm for bulky items. Test with your own products.
In the UK convention one micron equals four gauge, so 60 µm is 240 gauge. In the US, one mil is 25.4 µm and equals 100 gauge, so 60 µm is about 2.4 mil.
Film weight is roughly area in square metres × thickness in microns × the density of polyethylene (about 0.92 g/cm³). A 320 × 420 mm bag with a 50 mm flap weighs about 13 g at 50 µm, 16 g at 60 µm and 18 g at 70 µm, before adhesive and print.
Not always. Film structure matters too. Co-extruded bags combine several layers in one film, so a well-made co-ex bag can outperform a thicker single-layer bag. Test the actual bag, not only the number.
The 50-micron line in EU law was set for lightweight plastic carrier bags supplied to consumers at the point of sale. It is not a thickness requirement for mailing bags. Packaging minimisation under the PPWR is the more relevant rule for mailers.
This guide is general information based on published sources at the time of writing. It is not legal or tax advice.
Our free sample kit includes one of every product in the range, so you can pack your own goods in different thicknesses before you decide.