Acrylic engraving leaving little dots

[jkwilborn (Jack Wilborn)]

Seen this a few times… I think @ednisley nailed it here

Where Those Random Dots in Engravings Come From

It seems everybody engraving acrylic with a CO₂ laser has seen random speckles appearing in places where the design shows a blank. Regardless of the suggested remedy in the many threads on this topic, nothing stops the dots. It turns out the problem lies inside the high-voltage laser power supply, which occasionally fires the tube at random, even though the controller has disabled the supply’s output. Although I’ve measured only two power supplies, other folks report random dots regardless of t…

Don’t know what to tell you…