Nappalan leather is nubuck or suede with a thin layer of colour applied. Usually suede leather from goats or lambs for clothing leather are finished this way. It makes the surface smooth as with top grain leather. Such leathers are very soft and particularly light-weight. They are referred to as "silk leather" and the finish is called "nappalan coating". On the internet, the term napalan leather with one "p" also sometimes appears.
The thin colour layer is sensitive and makes the leather wear-sensitive (safety belt, carrying strap from bags). The surface is then visibly rough in such areas. The roughness of the suede under the thin layer comes back through. The coatings are available in matt and gloss finish.
The surface can be re-roughened with little mechanical stress.