Riasha Naidu, Managing Director of Unistar Inks, breaks down the concept of ‘blushing’ in ink. The first time someone told me, ‘The ink is blushing’, I thought, ‘fantastic now even the ink has feelings’. As if we don’t have to manage enough emotions on the production floor.
Was it shy? Embarrassed? Had someone complimented its colour? Sadly, the explanation was far less dramatic. Blushing is when a printed ink film develops a pale, cloudy or milky appearance. In solvent-based inks, this can happen when the solvent evaporates too quickly, cooling the ink film and allowing moisture to interfere with the resin and film formation.
High humidity, incorrect solvent blend, cold ink or substrate, and water-contaminated solvent can all contribute. The natural reaction is often to adjust the colour because it suddenly looks weak or washed out. But adding more base/toner won’t fix a moisture and solvent blend problem.
So, when the print starts blushing, it doesn’t need a confidence boost. Check the humidity and solvent blend.
UNISTAR INKS
unistarinks.com
