Vacuum Bags Explained: Why Thickness and Quality Matter
Two packs of embossed vacuum bags can look identical on the shelf and still perform completely differently once your meat, salami or cheese is sealed inside. This guide explains what actually separates a premium vacuum bag from a budget one: film thickness, what the film is made of, the embossing pattern, the seal and the way the bag is manufactured. That way you can compare bags properly before you buy.
It is natural to expect the cheapest bag to do the same job as a premium one. In practice, a bag that leaks, cracks in the freezer or will not hold a seal costs you far more than the few dollars you saved, because you lose the product you spent hours making, as well as your time re-sealing it.
Why thickness matters
Bag thickness is measured in microns (µm). Many budget embossed bags sold in Australia are around 70-90 µm. Our Italian embossed bags and rolls are made in 105 µm and a heavy-duty 140 µm film.
Thicker film uses more material, and in most cases that makes it the stronger bag. The difference matters most in the embossed channels, the textured side that lets the air escape. On a light film under about 95 µm, the plastic in those grooves can be as thin as 30-50 µm, and those thin spots are where bags tend to fail.
- 70-90 µm budget bags: fine for short-term storage of soft foods, but more prone to pinholes, cracking and losing vacuum, especially in the freezer or with bony cuts.
- 105 µm bags: a reliable everyday bag for most home vacuum sealing.
- 140 µm heavy-duty bags: the best choice for long freezer storage, curing projects, sharp or bony cuts and anything you cannot afford to lose.
What the bag is made of
A good vacuum bag is not a single layer of plastic. It is a laminate of two materials that each do a different job:
- Polyamide (PA, or nylon): the outer barrier layer. It blocks oxygen and gives the bag its strength and puncture resistance.
- Polyethylene (PE): the inner layer that touches the food and melts to form the seal.
The blend and the thickness of each layer decide how well the bag keeps food fresh, and whether it stays flexible and strong at fridge and freezer temperatures instead of turning brittle. Our heavy-duty Italian film, for example, is a 25 µm polyamide layer laminated to a 115 µm polyethylene layer, giving 140 µm in total.
The embossing pattern matters too
The textured side of an embossed bag creates channels so the vacuum sealer can draw the air out. The design and quality of that embossing make a real difference.
Smooth, deep dimples
Smooth, deep dimple patterns from modern tooling perform best. They keep their structure under vacuum so the film does not flatten and seal off the air channels too early, they let the air out quickly, and they give the sealer a solid surface to weld across.
Shallow dimples on thin film
When the dimples are shallow and the film is thin, the bag can twist and pinch as it is pulled tight under vacuum. Those pinch points become weak spots that can crack and let the bag open after it has been sealed. You then have to re-vacuum the bag or waste another one, and the problem can repeat. That is not good value, even if the bags were 5-30% cheaper.
Sharp diamonds and deep lines
Older designs with sharp diamond or deep-line embossing are best avoided. If the film is not elastic and well formulated, the sharp points of the pattern can become regular failure points. Again, a 105-140 µm film is far more forgiving.
A strong seal
The seal across the top of the bag is where your vacuum is held. A good bag and sealer combination should give you a solid, even weld at least 4 mm wide, with no wrinkles or gaps. A well-formulated polyethylene inner layer melts and fuses evenly, which is what makes that weld reliable.
Where and how the film is made
Many factors behind a bag's quality are invisible to the buyer: the quality of the raw materials, how consistently the film is produced and how closely the manufacturer follows food-contact regulations.
That is why we have supported Italian manufacturers for our embossed bags. Italian film producers are often leaders in manufacturing technology and modern tooling, and they work under strict European Union food-contact standards at every level of production. The same quality applies whether the bags go to commercial food producers or to home users.
Many vacuum bags sold online are unbranded "white label" products. The seller may not always know which factory made each batch or exactly which materials were used, so quality can vary from one order to the next. If a bag has no stated thickness, material composition or food-contact information, it is worth asking the seller before you trust it with your food.
We have used the same Italian producer for more than 12 years, and our customers consistently tell us the bags perform reliably, season after season.
The specifications of our heavy-duty Italian vacuum bags
| Property | Value | Test method |
|---|---|---|
| Film structure | 25 µm polyamide (PA) + 115 µm polyethylene (PE) | |
| Smooth side thickness | 140 µm | Internal method |
| Embossed side thickness (including texture) | 300-320 µm | Internal method |
| Overall weight | 137 g/m² | Internal method |
| Tensile strength | MD > 30, TD > 20 N/15 mm | DIN EN ISO 527-1-3 |
| Elongation at break | MD > 150%, TD > 200% | DIN EN ISO 527-1-3 |
| Oxygen transmission rate | ≤ 40 cm³/m²·24h·1 atm (23°C, 0% RH) | DIN 53380 |
| Water vapour transmission rate | ≤ 1 g/m²·24h (23°C, 85% RH) | DIN 53122 |
| Food contact | Suitable for food contact | |
| Recycling code | 07 (other plastics) |
MD = machine direction, TD = transverse direction. RH = relative humidity.
In plain terms: the low oxygen transmission rate is what keeps food fresh for longer, the high elongation means the film stretches around bones and sharp edges instead of splitting, and the low water vapour rate helps prevent freezer burn.
Is a cheaper vacuum bag really cheaper?
Bag performance also depends on how and where the bag is used: the sealer, the food, and the fridge or freezer conditions. But when a bag fails, you usually lose more than the bag. You lose the meat, the salami you have cured for weeks or the meal you prepared, plus the time spent re-sealing. Paying a little more for a thicker, well-made bag is usually the better value.
Tips for a reliable seal every time
- Leave at least 5 cm of empty bag above the food so the sealer has room to work.
- Keep the seal area clean and dry. Wipe off any fat, blood or marinade before sealing.
- Pre-freeze very wet foods for an hour or two so liquid is not drawn into the sealer.
- Wrap sharp bones in baking paper, or use a 140 µm heavy-duty bag.
- Check the seal is smooth and even, with no wrinkles, before storing.
Shop our Italian vacuum storage bags and Italian vacuum sealer rolls, browse the full vacuum bags and rolls range, or find the right vacuum sealer for your kitchen.
