If you have only used your laser unidirectionally for engraving, you may have never experienced a fuzzy edge.

But, if you use your laser bidirectionally then more than likely you have had at one time or even still fuzzy edges to your engravings, and no matter how much you try to focus the beam correctly they remain.

In many cases people just give up and blame the laser, and while the laser is the cause, there is a way to fix it.