Lanolin is a natural fat produced by the skin of sheep. It is extracted during the wool cleaning process.
 
It is very helpful when diapering with wool.
 
Thanks to lanolin, the wool diaper cover:
doesn't leak nor absorb the moisture
doesn't need to be washed after each use, an airing is enough.
is sel-fcleaning and hygenic.
Lanolin doesn't allow bacteria to grow in the diaper despite its so rare washing. You can safely use the wool cover for several weeks without washing and re-lanolinizing it.