- Jota Colour Code/Grain
~ 2 Black rings = mega coarse(MG) 425-500 μm Super coarse pre-grinding ~ Black ring = super coarse(SG) 151-213 μm Coarse pre-grinding ~ Green ring = coarse(G) 107-181 μm Pre-grinding ~ Blue ring = medium 64-126 μm Universal grinding ~ Red ring = fine(F) 27-76 μm Burnishing ~ Yellow ring = extra fine(EF) 10-36 μm Prefinishing of composites ~ White ring = ultra fine(UF) 4-14 μm Final finishing of composites and burnishing