What breathability actually means

Short answer: Breathability is a fabric's ability to let moisture escape. It depends both on how densely the fabric is woven or knitted and on what the fibre itself does with moisture. That is why a thick fabric can be breathable, while a thin one can feel closed and clammy.

Two halves of one idea

The word breathable is used for many things, but it covers two different mechanisms. One is about air passing through the gaps in the fabric. The other is about moisture travelling through the fibre itself. A fabric can be good at one and poor at the other. Once you understand both, it is easier to choose clothing to suit your needs.

Air through the fabric

A loosely knitted fabric lets air through, and that is the simplest form of breathability. The air carries heat and moisture out, and you feel it as a slight cooling. The more open the knit, the more air passes. On the other hand, a very open knit gives less warmth when it is cold. See our bamboo hoodie for women.

Moisture through the fibre

Some fibres move moisture through themselves, even when the fabric is dense. Moisture is drawn into the fibre on the inside and evaporates on the outside. That is the second half of breathability, and it matters because it works without large gaps in the fabric. Bamboo viscose is one such fibre, as in our bamboo sweatshirt for women.

Why dense fabrics can breathe

A tightly knitted viscose fabric can release more moisture than a loose synthetic one, because the fibre does the work. The synthetic fabric has gaps, but its fibre does not absorb moisture, so sweat stays on the skin until it finds a way out. The viscose carries it along. See our bamboo sweatpants for women.

Thick is not the same as closed

Many people assume a thick fabric is automatically warm and closed. But thickness and breathability are two different things. A thick sweatshirt in a fibre that moves moisture can feel drier than a thin top in a material that does not. The fibre decides whether moisture escapes, while thickness mainly decides how warm the garment is.

How to tell if a fabric breathes

You rarely notice it in the fitting room, but after an hour of wear. A breathable fabric still feels dry against the skin, while a closed one feels clammy, especially on the back and under the arms. Also notice how it feels when you come in from the cold. A breathable fabric evens out faster, so you do not feel damp.

Layer on layer

When you dress in layers, moisture has to get through all of them. A breathable base layer does not help much if the outer layer is completely closed. Choose layers that each let moisture pass, so it can make its way all the way out. A hoodie or sweatshirt over a viscose T-shirt is a simple combination for most days.

Care that keeps it breathable

The fibre's ability to move moisture can suffer if it gets coated in fabric softener. So skip the softener and use the amount of detergent given on the pack. Wash at a low temperature, preferably inside out, and let the clothes air dry. That way the fabric keeps its breathability and its soft surface for a long time.

Frequently asked questions

Does breathable mean the same as thin

No. A thick fabric can easily be breathable if the fibre moves moisture. Thickness and breathability are two separate qualities that do not follow each other.

How can you tell if a fabric breathes

After an hour of wear. A breathable fabric still feels dry, while a closed one feels clammy against the skin, especially on the back and under the arms.

Is bamboo viscose breathable

Yes. The fibre absorbs moisture and spreads it out so it can evaporate from a larger surface, even when the fabric is tightly knitted.