Colloidal latex is first mixed with formic acid to cause it to coagulate. The coagulum is processed in a "creping battery", a series of machines that crush, press and roll the coagula. The sheets are hung in a heated drying shed and then sorted by grade and packed for shipping.
There are several types and grades of rubber crepe, mainly distinguished by the grade and pre-processing of the latex used in their manufacture.
- Pale latex crepe (PLC) is a premium grade, made from raw field latex.
- Estate brown crepe (EBC) is made from "cup lump" (raw, naturally coagulated rubber from the collection cup) and other coagulum.
- Re-milled crepe is made from "wet slab coagulum" (cured latex, still wet from the coagulation tanks), latex sheets (unsmoked) and cup lump.
- Smoked blanket crepe is made from thick sheets of latex that have been processed in a smoker.
- Flat bark crepe is made from scraps and other poor quality raw product.
- Cecil, John; Mitchell, Peter; Diemer, Per; Griffee, Peter (2013). "Processing of Natural Rubber, Manufacture of Latex-Grade Crepe Rubber". ecoport.org. FAO, Agricultural and Food Engineering Technologies Service. Retrieved March 19, 2013.