This problem is usually observed on the bumper surface before printing. Causes and solutions:

Causes of Pad

• If this problem is caused by a very hard pad, a soft pad should be used.
• If the worn surface of the bumper is rough and porous, the bumper should be renewed.

Causes of Printing Block

• If the cliché is prepared with a raster that is not suitable for the image, or without a raster, a raster suitable for the design should be applied.
• If the depth of the cliché is too high, a cliché with less depth should be prepared. Or, the pause time of the buffer on the cliché or material should be increased.
• If the first exposure time is long during the preparation of the cliché, a new cliché with a shorter first exposure time should be prepared.

Causes of Ink

• If the ink is too thin, the amount of thinner should be reduced.
• If the ink dries slowly, fast thinner should be used or the waiting time of the pad on the cliché should be increased.

Material-Related Causes

• If the material surface is shiny, the surface should be cleaned or ink suitable for the material should be used.

Other Reasons

• If the pad pressure is too high, the pressure of the pad on the cliché and the material should be reduced.