Cardboard getting lighter instead of darker?

So, with all my research going on about my CO² Laser I came across the mentioning of the need for them to be run like once a week in order to keep the Gas activated which might actually be an issue as I only bought mine for recreational purposes and I’m not recreating all the time :sweat_smile:

So anyway… In order to not just be cutting garbage for the sake of keeping the Tube alive I decided to make a little Project that would swat two flies with one hit - Keep the Tube alive and serve a purpose:

:sparkles: Anodized Business Cards! :sparkles:

And for the Job to be an easy setup I decided to make a JIG to hold two Cards that would then get flipped over into the opposing cavity for the operation to be done a second time to engrave each Cards rear - EzPz :smirk:

Stupid as I am I went and fancied out on the JIG and did some unnecessary Markings on it like what it is for ( in case I forget until the next week :rofl: ) and where to put the Hold Down Pegs using a CAD Graphic of the 3D Printed Pegs I designed but when it got burned, I noticed the Cardboard getting lighter instead of darker.

The light parts of the Image were still lighter than the darker parts, so it wasn’t as if the Image was inverted - It’s just the material, while Scan Engraved, was getting lighter unlike when it is Cut where it does indeed get darker.

Am I scanning the image to fast / with not enough power? :thinking:

I don’t know if the result is directly related to your settings. Some materials naturally get lighter vs darker when engraved. Slate is a very common material where this is true although I’ve heard there are certain slates that behave differently.

If you explicitly want a darker engraving perhaps try defocusing so you can get the material to burn rather than ablate.

Didn’t even know that ablating is a thing and for it to cause a different effect but okay :thinking:
Gonna give it a try the next time :grin:

I’m only offering that as a potential solution since I’d think that cardboard should be burnable to a dark finish.

Other times you’d see this with paper would be in things like black cardstock. You could easily get a lighter outcome on the ablated portions of the material.

Here’s a two pieces of slate… both from CO2 44W machine.

An intersting note, I puchased some slate from home depot that was 1’x2’. Never could get a mark on it with the CO2.

I tried the fiber on it and it didn’t do anything to speak of… I lowered the frequency and increased the q-pulse width. Same speed/power…

It seemed to give me some destruction, so I ran the Mayan calendar on it… It completed ok and I went to lunch. While lunching, the spouse and I heard a big pop … couldn’t figure out what it was…

… this is what it was… This is a foot tall and 2 wide from this side… Guess it got a tad warm…


Wow… similar thing happened to me with our countertop when I was heating a bath of water using a sous-vide device.

Awesome calendar though.

Yea… kind of cracked up:crazy_face:

It is strange that the same speed/power settings don’t seem to have as much effect as frequency and q-pulse width…

Got a couple slate coasters, from the reject pile and I’ll see what I can do with those… I don’t think Russ Sadler had very good results with slate and a fiber, if I remember correctly… So many adjustments and each has such a wide range.

Russ set up a spreadsheet with frequency pulse values and duration for one of his customers, sent it to me for some guidance for some good combinations … still looking for them :face_with_spiral_eyes:


Don’t put your slate coasters in the reject pile. You would be amazed how good they look with 20 seconds on a belt sander. :beer:

I’ll try that…

Here is one of the coasters from the fiber… it was at 254dpi (0.1mm li)

Seems to work better than the CO2 does… :crazy_face: