My first experience with laser etching was with one of those little 6” cube things with about 300mW of power. It always gave me nice clean black text. I was using the laser to put my makers mark on the back on the flutes I make. The downside of the tiny laser cube is that it only has a working area of about 3x3”.
Then I got a 3018 Pro and put a 5.5W laser on it and then I started having trouble getting black etching.
Then I got a Creality Laser Falcon 10W and it is another step farther away from black etching. The only black I see is on my speed/power test in the burned out squares.
Trying to blacken tiny text or lines with a felt pen is prone to glitches when the pen jumps out of the groove and draws an unintended mark on the surface of my project. Also, touching end grain exposed in the etching tends to wick the felt pen ink, or paint, sideways into the wood which is even more untidy.
As I understand it the laser is not burning the wood but vaporizing it.
Perhaps there is some technique I am unaware of to restore the black text/graphics. Or perhaps it is simply that there is too much power in the laser to blacken the wood rather than vaporizing it. Perhaps a very low power setting would work? Or perhaps the very tiny focus of the laser is the problem. Maybe try it somewhat out of focus?
Anyhow, I’m sure I’m not the only person who has this problem so maybe this topic has already been worked on and someone already knows the solution.