This problem usually occurs when the pad is not able to take the ink from the plate and transfer it correctly onto the media. Causes and solutions:

Causes of Buffer

• If the bumper shape is not suitable, a more conical bumper should be tried.
• If the pad is too soft, a harder pad should be used.
• If the pad is worn, its surface is rough and porous, the pad should be renewed.

Causes of Printing Block

• If the cliché is too deep, the ink may accumulate on the pad and cause it to dry, in this case the cliché depth should be reduced or left to dry at certain intervals.
• Insufficient depth of the cliché may cause the ink to dry on the pad, in this case cliché at the appropriate depth should be used.

Reasons Caused by Ink

• If the ink dries quickly, a retarder or more thinner should be used.
• If the bumper is very wet and the film is not clear, quick thinner can be used.

Reasons Based on Material

• If the material surface is dirty, the printing surface should be cleaned and treated with alcohol depending on the contamination. The print operator can wear gloves to avoid problems.

Other Causes

• If the room temperature is too high, it should be brought to the 18-20°C range.
• If the printing speed is slow, the speed can be increased to prevent the ink from drying on the pad.