Start etching with Using Retina Energy.

thin:

medium:

thickest:

I tried to etch the DSAL. When I tried to first time, Only I could etch thickest wood. so I made laser's strength double, but It was not working. but When I controlled Z axis, I could close the distance between wood and laser, so It was working.

so. Wood's thickness is not problem to etch because I can control the distance.