Metallic Ink problems on Heidelberg press

Hi,

We recently aquired a UV CX Heidelberg 40". Every single time we try printing UV 877, or any metallic ink, we have major scum problems. We tried 3 different water solutions, different setting on press and different ink suppliers.

Anyone has some tips or lines we could follow to print those types of ink properly ?

Thank you very much

 

This problem is typical when printing metallic inks, when you try to match the pms book density with a single hit. When it comes to printing silver you will need to either deal with the scumming you describe or be willing to run it a little lighter than the PMS book. The other option would be to run 2 hits of metallic if you have an open printing unit. When it comes to printing all the other 800 metallic inks you could try to take a step up in the PMS book. For example.... if the job specs PMS 873 you could load the fountain with PMS 874 and just run it a little lighter. It will not be a direct match in hue, but you will be able to get a bit more weight while running a thinner and more manageable ink film thickness on your rollers. This thinner ink film will be a lot easier to keep clean. Most print buyers will be at a loss to tell the difference.