What is annaline?

It is the finish which is applied to
the top of the hide. 

All hides have a finish applied to
the grain.  (Hair side of the hide)
Annaline is a finish with no dyes
or pigments.  It is like if you took a
good piece of wood and would oil
the surface of finish it off with a
clear varnish. 
The oil or clear varnish cannot
cover any natural defects.

Nappa Leather: An old, often
misunderstood, designation of soft,
full grain leather. 
Many people believe, erroneously, that Nappa Leather is a synthetic
material.