Generic term for all types of leather with the natural surface of the hide (see grain split). Its texture can be smooth, grained, embossed or shrunk. The most important types of smooth leather are:
A very soft, non-slip, smooth leather that can be used for almost all purposes.
Aniline leather (nappa leather, natural)
A dyed-through leather, the natural pore structure (grain pattern) of which is clearly and completely visible. It may have a transparent, non-pigmented surface coating.
Semi-aniline leather (nappa leather, lightly pigmented)
An aniline leather that also has a lightly pigmented surface coating, without obscuring the natural pore structure (grain pattern).
Pigmented leather (nappa leather, pigmented)
Leather, the pore structure of which is covered by a pigmented surface coating of less than 0.15 mm.
A full-grain leather, the surface of which is given an attractive honeycomb-like appearance by a special tanning process.