Mottling

Too much water is being used; inks are over emulsified

Reduce water; adjust ink/water balance

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

Reduce water in prior unit

Stock is weak, or paper coating is too soft

Reduce ink with proper reducer

Excessive pressure exists between blanket and stock

Reduce pressure to press manufacturer’s specifications

Blanket is too hard

Change to softer blanket

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

Weaken ink strength by adding transparent white

Substrate is poor

Change to another substrate or lot of same material