Aniline leather

Aniline leather is the most natural-looking leather type and is coloured with soluble aniline dyes. Because it doesn't have a pigment based surface finish, aniline leather is a porous smooth leather. The natural texture of the skin is clearly visible and so aniline leather is usually classed as high-grade and with a price to match its status. The lack of a pigmented colour layer on the surface means that aniline leather feels natural, soft and warm to touch.

The pores of the skin must be clearly identifiable in aniline leather. At most, an aniline leather can have a hydrophobic treatment, provided that pigments are not included in the finish.

Aniline leather that is completely porous and without any finish is classed as pure aniline leather or just pure aniline. Soft aniline leather is also called napa leather.

In addition, leathers with velvet-like surfaces, such as suede and nubuck are included in the porous leather group.

The type of leather that can be classed as aniline is specified in national and international norms, regulations and standards. In Europe the term is defined by the standard: DIN EN 15987 "LEATHER - TERMINOLOGY - KEY DEFINITIONS FOR THE LEATHER TRADE" (July 2015). Under this ruling, an aniline leather is a smooth leather, where the pores of the hair are clearly visible. Any finish must not be thicker then 0,01 mm and should not contain pigments.

A wide variety of products are made from aniline leather. It is used as furniture leather, as handbag leather, for shoes or for clothing. Aniline leather is not really suitable for a car interior, as leather in cars is expected to be easy to clean and maintain. This can only be achieved by spraying a pigmented coating on the surface.

Structure of the leather colouring and finish. Without finish = aniline leather.

Because the surface structure is fully visible in aniline leather, only completely flawless hides can be processed. Any damages on the skin surface of the animal caused by horn scratches, goad marks, warts, insect bites and other markings such as fire-brands can leave visible scars. Such hides cannot be used for making aniline leather. Because the majority hides have some scars or damage, supply and demand dictates that aniline leather is generally more expensive than pigmented leather. Tanners state that less than 5% of the delivered skins can be processed as aniline leather.

Aniline is porous grain side leather. If you rub a drop of water onto it, it will penetrate and darken the surface. Aniline leather is therefore highly susceptible to water marks and grease stains as well as to fading caused by sunlight. Aniline leather generally has a warm and waxy grip and a low degree of gloss. Due to its softness, aniline leather is also called napa leather or, occasionally, soft leather.

Picture 1 shows a drop of water on a pigmented cowhide. Water does not sink in. Next to it, the drop sinks into the porous smooth leather.

Smooth leather, which has a low pigment coating and where the pore structure of the leather surface is still clearly visible is called semi-aniline. Since January 2016 there is a new leather term for a type of leather which is between aniline leather and semi-aniline leather (RAL 061 A1 - Germany). It`s called "Aniline leather, refined". Refined aniline leather is allowed to have a very fine pigmentation. Pure aniline leather is not allowed to have any pigments on the surface.

Video about different kinds of smooth leather.

Micrograph of the surface of an aniline leather. The porous nature of the skin can be clearly identified, which are not covered by a finish.

Aniline leather is used in all areas: Leather clothing, car leather, bicycle saddle, furniture leather, shoe leather, handbags and suitcases

Aniline leather is sensitive: grease stains - fading - water marks

Criteria of differentiation

Pure aniline leather: Pores are completely visible and there is no finish on the leather.

Semi-aniline leather: Pores are clearly visible, but a thin layer of paint is on the leather surface.

Pores are hardly distinguishable. A stronger colour layer is on the leather surface. Only a leather consultant or expert can investigate whether this leather may still be referred to as semi-aniline leather.

Pigmented smooth leather: Pores are no longer distinguishable. The leather has a thick layer of paint.

Sometimes leather which is not aniline is offered as such. Since aniline is particularly sensitive, occasionally a gentle layer of finish is applied. Technically, such leather is no longer aniline. Depending on the amount of surface colour applied, it can be identified as aniline leather, refined or semi-aniline leather or very rarely pigmented leather.