Calcium content of pigment is above limit
Check calcium level of pigment - higher caIcium means high probability of lumping
Fount solution react with ink in dummy area
Check fount with ink interaction , Agitate ink dummy area to avoid any stagnancy/solidification
Roller glazing areas more prone to cause lump
Especially Magenta unit is prone to get glazed maximum, check roller condition & de-glaze it, with proper solution.
Water hardness is more than desired level
More hardness in water also shall create lump, Adjust water hardness within 8 Deg to 12 Deg German Hardness.
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