| Possible Causes | Solutions |
| Rough paper, strong penetration and absorbency | Increase the viscosity of varnish |
| Insufficient varnish consumption | Increase the ink distribution |
| Low viscosity and solid content of the varnish | Dry the ink before applying varnish |
| The ink on the surface is hard to dry | The paper is rough, apply the paper with glue at the bottom |
| Low temperature and high moisture content | Rise the temperature of the environment and heating section |
| Poor quality of varnish | Change a better one |
