Hi All,
I’m running into an issue with banding across an image when text is introduced. The following was burned into black painted glass at 200mm/s, 17%max , 5%min @ 300dpi using dither. The text is burned in and the file was created in photoshop as an exported png as a negative.
As you can see, there is banding in the image when it gets to the bulk of the text. It looks as though after burning a line of text the laser takes time to recover to full power. Im unsure how to proceed, but thinking maybe it’s the fact that the text was the only area of the photo to be full black and the power range isn’t great enough? Is there a setting I messed up or should be using?
I’ve never had this happen before with any of my burns, lol time to learn something new… I hope!
I’d like someone else more familiar with your equipment to weigh-in but I suspect it’s because your 50W CO2 tube is having a difficult time modulating at the lower end of its power band. Especially for the areas that are meant to be dark but are showing up light. Basically it’s trying to apply a very light power but can’t quite manage so it overburns those spots.
By the way, I’m assuming this is a white substrate with a black coating. Please correct me if I’m wrong.
You may want to try going faster to see if you can raise the power band a bit to see if changes the result.
[EDIT] Just read something else that might make this irrelevant. Seems Min Power is not used with Dither image mode, only max power. 17% should be perfectly within the addressable range of your 50W.
Yeah, that’s what I was thinking. That the power was too low and that maybe the power supply couldn’t respond quickly enough. However, if that’s how dither works then it definitely rule that out. I’m not entirely sure though as I ran tests and the low end seemed to make a difference?
This is a glass substrate, painted matte black on one side and then sprayed with a pearl white after engraving.
