Need help: Inconsistent laser engraving (empty patches)

[silver1177 (Steve B)]

Hey everyone,
I have a Creality Falcon 10W (diode laser), GRBL firmware, using the latest LightBurn version on my MacBook Pro. The material I’m working with is sheets of icing paper.

I’ve been using this material consistently and even did a material and interval test to find the proper settings.

However, as you can see in the photo, between two separate jobs with the same image and settings, one comes out pretty clear while the other has empty patches.

Also, the original file is a png sized accordingly in photoshop before import (not a vector image).

Is my issue a settings problem or a file type issue? Also, I have no idea why a solid black bar is showing up like that too. I’ve consistently had issues with the start of engravings having empty patches like this (the engraving begins at the base).

Attached below:
1.) photo of original file
2.) photo of the laser engravings
3.) photo of current settings
4.) photo of materials test

[Pete.IRL (Peter O D)]

Hi Steve
Pete the newbie here. First thing is dont do anything till real knowledge arives to help out!
Have you got air assist on for cutting.
Am I seeing outlined squares overlapping cut squares…row 1 starting from 40% - 100%.
Was the paper flat during operation and is it cut/placed square, I see lines running off in the outline of the settings test.
Is the laser module fitted tight enough and properly orientated…vertical etc.
Could there be some residue on the paper thats reflecting the laser…so not marking at blank spots.
Are you using ventilation.
What is that paper made of
Is your frame frame square and belts tightened properly

[JimNM (James)]

You are set to image. You will be better served by using the TRACE command to change the image to an object.