AbstractGet full access to this articleView all access options for this article.Get accessReferences1. Fearn T. , “Flat or natural? A note on the choice of calibration samples”, in Near Infrared Spectroscopy Bridging the Gap between Data Analysis and NIR Applications, Ed by Hildrum K.I. Isaksson T. Næs T. Tandberg A. , Ellis Horwood, New York (1992).