I don't understand it either, but basically it explains two modes of rubber production(?). This is all very fascinating, but I'm having troubling understanding where it fits into the autochrome.
Ok... here's what I found to give some background for those as clueless as me...
Smoked rubber: a type of crude natural rubber in the form of brown sheets obtained by coagulating latex with an acid, rolling it into sheets, and drying over open wood fires. It is the main raw material for natural rubber products Also called ribbed and smoked sheet. Compare crepe rubber
Crepe rubber: a type of crude natural rubber in the form of colourless or pale yellow crinkled sheets, prepared by pressing bleached coagulated latex through corrugated rollers: used for the soles of shoes and in making certain surgical and medical goods Sometimes shortened to crepe. Compare smoked rubber