Cutting & etching

Does anyone have any tips on cutting & etching 1/4" walnut?

Here is where you can get the suggested settings:
http://www.laserengraverforum.com/viewtopic.php?t=7499

Ours are the 130 watt version. I didn’t see walnut but cutting 1/2" cherry was 60% power and 8mm speed. Engraving was 10% and 500mms.