Roller Marks

Bands of ink that form and look like rail road tracks. They appear on the roller train and may transfer and appear in the print. They may appear in rows across the sheet anywhere from the lead edge to the tail edge.

CAUSE CURE
Emulsified ink build-up at the nip of the dampening form/distributor roller. Check roller setting and pressures from the Dampening form and distributor. Reset as necessary.
Contaminated ink train Wash roller train thoroughly
Ink build-up on the edges of solids and pictures Reset ink keys on the edges to push less ink. This can also be adjusted by lowering the ink sweeps one or two points.
pH/Conductivity out of spec Check pH and conductivity and set to manufacturers spec.