This burning was done on white pine wood, which is very soft and takes heat very easily. For the dark outlines, I had heat at about 90/105. For the shading and interior details, I turned the burner down to about 85.
What at a lower heart, though burners slower, you get more of a crisp line for details. When using hotter heat, though burns extremely fast, the heat cause the burn marks to look almost blurred like they are bleeding as paint does.
All wood is different though how it reacts to heat depending if is a hard or soft wood. I enjoy using softer woods to burn on for signs plaques etc. and harder woods for cutting boards, charcuterie boards, and other food related things.