Cotton or poly-cotton for South Africa's climate

Buyers in this market are precise about GSM and vague about fibre, which is the wrong way round. Forty grams changes how a tee hangs. Changing from cotton to poly-cotton changes how it behaves in heat, in the wash and under a print head.

Here is what each one actually does.

What the three options are

	Composition	Where it belongs
100% cotton	Combed or carded cotton, usually single jersey	Retail, premium corporate, anything sold on feel
Poly-cotton	Commonly 65/35 or 50/50 polyester–cotton	Corporate uniform, hospitality, high-wash programmes
Performance polyester	Micro-polyester or poly-spandex	Sport, team kit, active use

We knit all three. The choice is genuinely driven by end use, not by cost, though cost tends to follow.

Heat: it depends what the wearer is doing

The common shorthand is “cotton is cooler”, and it is only half right.

Cotton absorbs moisture. It holds it in the fibre, which feels cool and comfortable while the wearer is fairly still. Once it is saturated it stays wet, gets heavy, and stops helping — which is why a cotton tee is pleasant in an office in Johannesburg and unpleasant on a warehouse floor in Durban by mid-afternoon.

Polyester moves moisture. It absorbs very little and transports it to the surface, where it evaporates. It feels less soft against the skin but it does not get waterlogged, and it dries far faster.

Poly-cotton sits between, which is why it dominates uniform programmes. Enough cotton for hand-feel, enough polyester to keep working when the wearer is active.

So the honest answer for South Africa is not one fibre. It is: cotton for retail and for people who sit down, poly-cotton or polyester for people who move.

The laundry is where corporate programmes are decided

For anything washed weekly for two years, this matters more than the wearing comfort.

Polyester content brings three things a commercial laundry rewards:

• Less shrinkage. Cotton shrinks; polyester essentially does not. A 65/35 blend moves far less over its life than 100% cotton.
• Better shape retention. Collars and hems hold their line longer.
• Faster drying, which is a real cost line for anyone laundering in volume.

What it costs you is hand-feel and, on cheaper blends, pilling — polyester pills differently from cotton and the small fibre balls are more visible on a dark uniform.

If you are running a corporate or hospitality programme, this is usually the argument that decides it. If you are selling to a consumer who touches the garment before buying it, it is not.

Print behaves differently on each

This catches people out, and it is not fixable after the fact.

On cotton: screen printing with plastisol, water-based or discharge inks all work. Discharge and water-based sink into the fibre and keep the fabric soft, which matters on a garment somebody chooses to wear.

On polyester: standard plastisol is a problem. Polyester dyes can migrate into the ink over time and discolour the print — the reason a white print on a red polyester tee can turn pink months later. The correct routes are sublimation, DTF, or a plastisol with a proper blocker base.

On poly-cotton: somewhere between, and it depends on the ratio. Test it rather than assume it.

Whichever you choose, wash-test the decoration on the pre-production sample before the bulk print run. Five domestic cycles. This is the cheapest insurance in the whole process.

Cost, honestly

Polyester is usually cheaper per kilogram than combed cotton, so a poly-cotton tee at the same weight often costs less than a 100% cotton one. That is a real saving, and it is also why poly-cotton sometimes gets specified for the wrong reasons.

Two things worth being clear about:

• Choosing poly-cotton to save money on a retail garment is usually a false economy. The customer notices the hand-feel, and hand-feel is most of what they are buying.
• Choosing 100% cotton for a uniform programme because it sounds better is also a mistake. It will shrink, it will need replacing sooner, and the laundry cost is yours or your client’s.

Pick from the end use. The cost difference will follow, in whichever direction.

Then pick the weight

Fibre first, weight second — they are separate decisions and conflating them is how specs go wrong. Once the fibre is settled, 180 or 220 GSM is the next question, and how to specify a weight so you get what you ordered covers tolerances and the questions that go with the number.

The underlying logic of what a weight figure does and does not tell you is the same in every market — the full explanation is worth reading once.

A short answer if you want one

End use	Our recommendation
Retail tee	100% combed cotton, 180 GSM
Premium retail	100% combed cotton, 220 GSM
Corporate uniform, office	Poly-cotton 65/35, 180–200 GSM
Corporate, active or outdoor	Poly-cotton or performance polyester
Promotional giveaway	Cotton or poly-cotton, 150 GSM
Sport and team kit	Micro-polyester or poly-spandex, 120–180 GSM

These are starting points, not rules. Tell us what the garment has to survive and we will argue with the table if it is wrong for your case.

One caveat worth stating: a supplier who cannot knit both will recommend whichever they can get. That is a reason to establish whether you are talking to a factory before you take a fibre recommendation at face value.

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We knit cotton, poly-cotton and performance polyester in Tirupur and ship into Durban, Cape Town and Port Elizabeth for South African buyers, from 300 pieces per style per colour. If you are not sure which fibre the programme needs, describe the end use and we will tell you — including when the cheaper option is the right one.