Microporous membranes are defined as a thin-walled structures having an open spongy morphology of precisely controlled pore size typically ranging from 0.03 μm up to 10 μm in diameter. Simply put, lots of tiny holes that allow airflow to pass through them but not water droplets, so you stay dry whilst still allowing perspiration to pass out of the garment.

Hydrophilic membranes by contrast are solid films that lack any visible holes, as a result, they provide complete protection against wind. However, these membranes have the ability to allow moisture in liquid or vapor form to travel through them in only one direction.

This is achieved through molecular diffusion, where moisture moves from areas of higher temperature to areas of lower temperature. Although it may seem contradictory for a membrane without holes to be able to "breathe," it does transfer moisture effectively, creating a microclimate that keeps you dry inside the garment. In our opinion, if the inside of the garment remains dry, then it can be considered as breathing effectively.