White ink turns pink when printed on a black plastic board.

When printing Bai Mo, the surface treatment of black plastic plate is not enough, which leads to insufficient adhesion of Bai Mo, and thus discoloration occurs during printing.

The following measures can be taken to solve this situation: 1. Pretreatment of the surface of black plastic board, such as sandblasting and scraping, can increase its surface roughness and enhance its adhesion.

2. Change the Bai Mo brand with better use effect, or change the printing process.

3. Adjust the printing parameters of the printing machine, such as printing speed, temperature and pressure, to achieve better printing effect.

4. Color Bai Mo before printing to increase its stickiness and adhesion.

Different plastic materials and printing methods will also affect the printing quality, which needs to be adjusted according to the specific situation in actual operation.