Micron, mu and gauge all describe the same thing: how thick the stretch film is. Micron and mu are the same unit (µ), used in the UK and most of the world. Gauge is an older measure still seen on some imported films. Thicker film has more material in it, which generally means more strength and puncture resistance.
If you only remember one thing: in the UK you buy stretch film by micron, and higher micron means a thicker film. Everything else on this page is detail.
What a Micron Actually Is
A micron (µ) is one thousandth of a millimetre. So a 17 Micron film is 0.017mm thick and a 23 Micron film is 0.023mm thick. Those numbers sound tiny, and they are, but the difference between them is real. A 23 Micron film has about a third more material than a 17 Micron film, and you feel that difference when you wrap a heavier or more awkward load.
“Mu” is just how the symbol µ gets written or spoken when the special character is not available. If you see “17mu” and “17 Micron” and “17 micron” on different listings, they all mean the same thing.
Where Gauge Comes From
Gauge is an older unit that came out of imperial measurement. You will still see it on some films, particularly ones imported from markets that historically used it. It measures the same physical thickness as micron, just on a different scale, which is why a conversion is needed to compare the two.
As a rough guide, gauge is close to four times the micron figure. So a film around 17 Micron sits near 70 gauge, and a film around 23 Micron sits near 90 gauge. These are approximate. If a supplier only quotes gauge, ask for the micron figure so you can compare like with like.
Why Thickness Matters
Thickness affects three things you care about.
Strength and puncture resistance. A thicker film resists tears and punctures from box corners and sharp edges better than a thin one. If your film keeps splitting mid-wrap, thickness is often the cause.
Load holding. More material generally means the film can apply and hold more tension without failing, which keeps heavier loads tight.
Cost per roll. More material costs more. A thicker film has a higher price per roll, which is why it is worth matching thickness to the load rather than always buying up or always buying down.
The mistake buyers make is treating thickness as a single “more is better” dial. It is a trade-off. Over-specify and you pay for material you do not need. Under-specify and you pay in failed wraps and damaged stock, which costs far more than the film ever would.
Which Thickness Should You Use?
We supply hand film in two thicknesses, and the choice between them is straightforward.
17 Micron suits lighter, stable, uniform loads: standard boxed goods that stack squarely and do not have sharp edges poking out. It uses less plastic and costs less per roll. Our 17 Micron roll weighs about 1.87kg on a 400mm by 250m roll.
23 Micron is our heaviest hand roll. It has more material, so it handles heavier pallets and more demanding manual wrapping where a thinner film would struggle. Our 23 Micron roll weighs about 2.43kg on the same 400mm by 250m roll.
When you are genuinely unsure, 23 Micron is the safer pick. The extra material gives you more margin against the load, and the cost difference per pallet is small once you account for the wraps you save and the failures you avoid.
Micron Is Not the Only Number That Matters
Thickness gets all the attention, but it is only part of the picture. Two other figures decide how much film you actually get and how far it goes.
Roll length. A thicker film on a shorter roll can give you fewer metres than a thinner film on a longer one. Always check the length. Our rolls are 250m regardless of thickness, so you can compare 17 Micron and 23 Micron directly.
Roll weight. Weight tells you how much material is on the roll. Two rolls quoted at the same micron can hold different amounts of film if one is short-wound. Published weight, like our 1.87kg and 2.43kg figures, lets you check you are getting what you pay for.
When you compare suppliers, compare micron, length and weight together. A cheap headline price on a roll with less film on it is not cheap per pallet.
Frequently Asked Questions
Is 17 Micron or 23 Micron better?
Neither is better in general. 17 Micron is right for lighter, stable loads and 23 Micron is right for heavier or more demanding ones. The better film is the one that matches your load.
How do I convert gauge to micron?
Divide the gauge figure by about four to get an approximate micron value. So 90 gauge is roughly 23 Micron. It is approximate, so ask the supplier for the micron figure when you can.
Does a higher micron mean the film stretches less?
Not necessarily. Stretch depends on how the film is made, not just its thickness. A thicker film usually holds more tension, but you should not assume thickness alone tells you the stretch.
Why does my thin film keep tearing?
The most common reason is that the film is too thin for the load, especially if the load has sharp corners or heavy items. Moving up to 23 Micron usually solves it.
Is thicker film always worth the extra cost?
No. If your loads are light and stable, a thicker film is material you are paying for and not using. Match the thickness to the load rather than always buying the thickest available.
Conclusion
New to buying stretch wrap? The Complete Guide to Stretch Wrap Film covers hand vs machine film, cast vs blown, and how to choose between them.
Micron and mu are the UK measure of stretch film thickness, and they mean the same thing. Gauge is the older equivalent, roughly four times the micron figure. Thicker film gives you more strength and holding power at a higher cost, so the sensible approach is to match thickness to your loads: 17 Micron for lighter, stable pallets and 23 Micron for heavier or more demanding ones. And whichever you choose, check length and weight alongside micron so you know exactly how much film you are getting.