Positive printing lines

Problem case

What causes positive printing lines
Positive Doctorblade Lines, also called railroads or streaks, usually moving with
the doctor blade oscillation. Clearly visible in engraved and non-engraved areas. Those problems are mostly caused by contamination of ink or pressroom parts, such as ink filtration and ink tanks. Incorrect cylinder finish in copper & chrome also can be a reason.

Solution

Solutions for positive printing lines
1. Check ink for dirt and foreign particles, clogged filtration, use clean ink pan before printing. Change ink if necessary.
2. If particles are stuck to the doctor blade tip, clean with chopstick or carefully polish cylinder with fine sandpaper.
3. Check gravure cylinder for Rz values and repolish cylinder surface if necessary.

TKM recommends TKM Ceraprint for halftone and vignettes.