DMTīs come in the following grits:

coarse: Mesh 325
Fine: Mesh 600
extra fine: Mesh 1.200

The DMT coarse, 325 is the recommended grit size for lapping purpose.
You might want to read further posts about lapping with the dmt.
You remember, the DMT from Olivia are the small versions.
These are actually smaller than most stones to be lapped.
You might want to reconsider this fact.
It is popular belief that a lapping stone should be as big as or slightly bigger than the stone to be lapped

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