DMR's manual says mushrooms of 4 to 5 cm cap diameter with a firm cap and a closed veil are ready. The Hindi farmer folder says pick at 3 to 4 cm while the cap is still closed.
Both are DMR and both are correct for the market they describe. The veil is the thin skin joining cap edge to stalk. Once it tears the gills show, the mushroom loses weight and colour fast and the grade drops.

