Mottling

Paper has an uneven surface

Check paper for texture and absorbency. Try a different stock

Too much water is being carried; inks are water-logged

Reduce water; adjust ink/water balance, check chemistry

Too much water is present in prior unit; water is left on sheet

Reduce water from prior unit

Stock is weak or paper coating is too soft

Reduce ink tack

Excessive pressure exists between blanket, plate and/or stock

Ensure all pressures and packing are within manufacturer’s specifications

Blanket is too hard or glazed

Change to softer blanket or deglaze

Ink is too strong; insufficient ink is being carried to the plate

Weaken ink strength by adding transparent white