Photo prep & etch on slate advice seeking

[Localmandave (Dave Henry)]

I have just made the jump to Lightburn and looking to etch slate, I have done a few basic pics but now struggling to get a good output

which was using laserGRBL, I got the lion after a few goes which I was really pleased with but other images I just want the subject not a white burnt background, machine is a 3018 (non branded) running a woodpecker board, 7w laser, Last top image getting better

Current settings
$0=10

$1=25

$2=0

$3=2

$4=0

$5=0

$6=0

$10=1

$11=0.010

$12=0.002

$13=0

$20=0

$21=0

$22=0

$23=0

$24=25.000

$25=500.000

$26=250

$27=1.000

$30=1000

$31=0

$32=1

$100=800.000

$101=800.000

$102=320.000

$110=2200.000

$111=700.000

$112=600.000

$120=1000.000

$121=1200.000

$122=30.000

$130=250.000

$131=250.000

$132=200.000

Any help would be great, thanks in advance

[Bonjour (Bo)]

@Localmandave

I have just made the jump to Lightburn and looking to etch slate, I have done a few basic pics but now struggling to get a good output

which was using laserGRBL, I got the lion after a few goes which I was really pleased with but other images I just want the subject not a white burnt background

Invert your image, cut away the stuff you don’t want - nothing magic about your machine or the image, just need to understand that what you burn turns white on slate, what you burn turns black on organics.

To increase contrast, I rub the slate with a drop of machine oil (sewing machine oil/3-in-1 oil). Just a small drop will coat the entire 100x100mm slate and will harden off in an hour or so.

I’m not a fan of polyester sprays, as they tend to flake off with time and don’t handle heat as well as just plain old (and cheap!) oil.