In the High-quality Mode, the laser travels across the entire width of the job at the same speed marking only the defined areas for the engraving. That means that jobs are engraved at the same speed across the entire engraving surface. The result is a very even and homogeneous laser engraving.
When the High-quality Mode is not activated, the head usually travels at a higher speed but only over the width of the area to actually be engraved. The result is different exposure times and the material is engraved more deeply in some places.
Summary: Always activate the High-quality Mode when a high-quality engraving is desired and the length of the engraving time is not critical.