6c Abrham Lincoln (Scott 186-195?)

I need help. how to classification scott? thanks

Scott 159. Continental Bank Note Co. hard paper (with clear straw fibers). Some specialists, such as Wiley in 1913, used to classify this as 'straw paper." However recent analysis by John Barwis showed that this is merely a grade of normal hard paper with some poorly digested fibers. It is therefore at best a minor variant and not a distinctive paper.

Yours is a nice clear example of this variety.

thank you very much