During the printing operation the highlight dots start to form into a “donut” shape, where the center of the dot no longer is transferring ink.

CAUSE CURE
Dried Ink Particles. Avoid dry ink “skin” when removing from kits or cans, clean press thoroughly and remove all dried ink. Pevent ink from drying up on ends of rollers by lubrication and/or manual washing. Filter ink if being pumped from totes or drums.
Rubber roller is breaking down and releasing particles. Recondition rollers and replace if necessary.
Excessive glaze buildup is breaking away from rollers. Use a good glaze remover to clean rollers, or scrub rollers with pumice powder and solvent to remove glaze.
Breakdown of dampener rollers or sleeves due to wear. Replace suspect roller or sleeve in dampening unit.
Foreign particles, dirt, and debris falling into press. Clean the areas above the press, wash up press, and clean plates.
Loose paper dust, fibers, and coating on web. Vacuum the web of paper, run the web through a dead unit, or consult paper supplier.
Too tacky of ink picking apart the surface of the paper. Reduce tack of ink, consult paper supplier for better paper stock.
Blanket becoming tacky and picking the surface of the paper, rubber is being reverted. Wash blanket with a rubber rejuvenator or replace blanket.