Plate is damaged with little cracks when using water based inks. Such fissures are evident both on plate surface and on printed product.
This particular issue happened in a plant printing corrugated post-print with water based inks.
The water based inks are characterised by the presence of amines in the formulation and have a rather high pH value (~8,5÷9,5). These features tend to weaken the plate surface after a prolonged contact.
In this case the plate was not properly cleaned after printing and the ink was left drying on the surface.
The ink has a little shrink during drying and this has created tension on the printing surface of the plate that cracked.
Further activities on reprints have worsened the problem.
Clean your plates thoroughly after printing and don’t let the ink, especially if water based, dry on the surface.