Porous leather - Open-pored leather
For the cleaning and care of leather, as well as the sensitivity of leathers, the distinction is always made between porous and leather finished with a protective layer. Porous leather is highly sensitive to liquids which are easily absorbed, causing permanent stains.
To find out if leather is porous, simply rub a drop of water with your finger in an unseen area. If the drop penetrates into the leather, it is porous. In most cases, this area becomes darker. If the drop runs off, then it is not porous.
It is similar with wood. Unpainted wood is open-pored and liquids are drawn in and lacquered wooden surfaces are protected by the varnish against liquid penetration.
Porous smooth leather
The open-pored leathers include the porous smooth leather as well as all velvet-like leathers, such as nubuck and suede. The most porous smooth leather is aniline leather. On the other hand, leather coated with a film (including patent leather) is neither open-pored nor breathable.
Strongly pigmented leather.
Partially porous smooth leather
There are leather types such as semi-aniline leather or oiled, waxed and greased leather, where the porosity differs. Only the cautious rub test (to avoid stains) in an unseen area helps to check whether the leather is porous or not. If moisture penetrates, caution is advised in daily handling as well as during cleaning and care.
Pull up leather, greased leather, waxed leather and oiled leather is more or less open-pored.