What problems may occur when printing circular colored copperplate paper?

When printing circular colored copperplate paper, the following issues may occur:

1、 Problems caused by the characteristics of paper

Powder shedding and stretching variation:

Due to process defects, some domestically produced copperplate paper is prone to varying degrees of powdering and stretching variation, especially single-sided coated paper, which is prone to curling and affects the accuracy of overprinting.

Poor ink absorption ability:

Copperplate paper has a smooth surface and poor ink absorption ability, which may result in uneven ink layers or unclear imprints during printing.

Problems caused by excessive paint:

Copperplate paper often experiences powdering and black shadows on the printed surface during the printing process due to the high amount of coating. This may be due to excessive pressure on the paper surface, which crushes the coating powder on the surface of the copperplate paper, causing powdering and black spots.

2、 Problems caused by printing technology

Sticky and slow drying:

Excessive printing pressure or high ink viscosity may cause the ink to not dry in a timely manner, resulting in sticking and dirtying. Meanwhile, slow ink drying speed can also affect the quality of printed materials.

Unclear imprint of the branch:

Excessive printing pressure may result in unclear dot imprints, affecting the clarity of printed materials.

Page layout:

When the printing pressure is insufficient, it may cause the layout to become blurred, affecting the overall aesthetics of the printed product.

Overprinting defects:

In the process of multi-color overprinting, improper control of ink viscosity, dryness, etc. may lead to poor overprinting, color deviation, or missing prints.

3、 Problems caused by ink blending and selection

Improper selection of base color:

When printing trademarks and packaging products on copperplate paper, a light color is often used as the base color, which is then overlaid and printed. If the base color selection or blending is improper, it may affect the color effect and quality of the printed matter.

Poor ink quality:

The use of poor quality ink may lead to color deviation, powder loss, decolorization, and other issues in printed materials.

4、 Problems caused by improper anti sticking measures

Copperplate paper has weak ink absorption and a smooth back, making it prone to sticking and dirtying when printing on surfaces with high ink exposure or multi-color overlay printing. If the anti sticking measures are improper, such as using too much or too little anti sticking agent, it may affect the quality of printed materials.

5、 Other precautions

Pad technology and printing pressure adjustment:

Pad technology and printing pressure adjustment are key to ensuring even and bright ink layers in printing. The printing pressure of copperplate paper should be uniform and appropriate, and the lining should be made of neutral hard material.

Ink adjustment:

When printing large format solid editions, it is advisable to achieve "deep ink thin printing" as much as possible, that is, to adjust the ink depth appropriately, so that the ink layer is correspondingly thinner during printing, which can meet the requirements of printing color, reduce the chance of overprinting, and prevent color stacking from not being printed.

In summary, when printing circular colored copperplate paper, attention should be paid to paper characteristics, printing technology, ink blending and selection, anti sticking measures, and other related precautions. Only by comprehensively considering and properly addressing these issues can we ensure the quality and effectiveness of printed materials.