Mottling/Poor Solids

Printed solid areas are not uniform or smooth in appearance. Ink density is uneven or light.

Cause Cure
Stock has a non-uniform surface. Consult paper supplier for better grade of paper. Consult ink supplier for an ink that will minimize the problem.
Too much printing pressure. Reduce pressure, check blanket packing and gauge, check press settings.
Improper setting on ink rollers, or rollers are in poor condition. Check ink roller settings and reset to specifications. Check roller condition and durometer.
Improper ink and water balance Adjust ink and water settings, usually reducing the water and ink will help the most.
Blanket needs to be replaced, or has become worn in certain areas, or has been contaminated by chemistry or paper fillers and coatings. Replace blanket or properly clean blanket. Consult blanket manufacturer.
Poor ink transfer or laydown. Consult ink manufacturer.
Plate image area not accepting and transferring ink properly. Check to make sure plates are being processed properly. Consult plate manufacturer.
Lack of impression. Check blanket height.
Improper fountain chemistry mix and or poor dampening Check for proper dosage of chemistry and check dampening rollers for uniform application.