Search Branch offices
Heidelberger Druckmaschinen AG
Heidelberg Australia and New Zealand
Home > News & Events > March 2007 >  Tips: Darkening

Darkening

When ink darkening occurs, the darker colours are transferred from the blanket over the printing plate onto the succeeding inking system, where they contaminate the light colours.

During wet-on-wet printing, the tackiness of the inks must be correctly formulated. Nevertheless, it can happen that the darker colours from the first printing units contaminate the lighter colours (mainly yellows) in the printing units.

Remedy:

  • Change to a different tack of ink
  • Print lighter colours first
  • Check that the screen rulings are correct for the press colour sequence
  • Check that the fount chemistry is correct (PH, Alcohol and IPA)
   
Tips & Tricks
Find out more Tips & Tricks here.
  Decrease in Tone Value
  Darkening
  Horizontal Stripes
  Mottling
  Ghosting
  Emulsification
  Picking
  Crease Formation
  Electrostatic Charge on Paper
  Inking Roller
POLAR Cutting Tips
This series of POLAR Cutting Tips helps to increase the machine performance and its efficiency.
  Pre-jogging Quality Checks
  Stripes on the Cut Edge
  Four-side Trim
  Angular Cut
 
  About Us   |  Contact Us   |  Careers   |  Print Media Academy   |  Download Center  
Glossary    Site Map    Products A-Z    Privacy Statement    Legal Notices    Heidelberg web access   

© Heidelberg Australia / New Zealand Inc. All Rights Reserved