How to make laser marking machine marks clearly?

You bought a laser marking machine, but the marking results are not clear enough, you think the laser power should be higher, 80%, 90%, 95%...  

The operation is wrong,  

when marking small characters and fine text, the fill method must be set to bidirectional fill. set the line spacingto 0.03-0.08.

The power only affect depth,  does not affect the clearance.