We have printed a CMYK + metallic gold PMS 872 on uncoated paper. After a few weeks the gold turns green Can anybody help ?
Yes Hi Richard, Yes I've spoken to him, and a few more, but nobody knows what it is. We have now printed the same job again, with different paper, ink, and fountain solution, but it just turned green again
That sort of points the finger at the ink. Have you tried Schlenk Lithogloss Gold? I just checked a 6 month old pass sheet and it's not turned green. Errr...are you using any kind of water based emulsion coating by any chance? Or water based sealer?
We haven't tried that type of gold, and we didn't use any kind of sealer! The strange thing is that we have printed the same job for the last 10 years without any problems
OK I wonder if the RH% in your local area is high? Denmark, close to open sea, extra ozone etc. Could be the atmosphere itself is affecting the ink. Just a long shot but you could try sealing the print with a traditional oil-based varnish? That shouldn't affect the look and feel of the print but may prevent the humidity from oxidising the metallic. Good luck!
