This may be a dumb question but

I’m trying to figure out my new laser, omtech 100w CO2. I’m working with clar bricks, trying to get a nice black contrast in letters. Some of the issue is the brick itself, but I can’t help feeling I can do better on the lettering. I’m running 2 passes at 50% and 160mm/s, .055 interval.

I watched a video saying to get the temperature hotter, to engrave as a vector. Since I’m just using basic text from lightburn, can I do that? Are non image fonts raster or vector? If they are raster, how do I change/convert them to give it a shot?
I realize the simple answer here may be to turn up the power, but before I do another run at say, 70%, I wanted to see.

Pics include the red clay brick, and tan firebrick

There has to be something inherent in the material that heat will turn it black. There might not be a viable way to turn red brick black.

The fire brick is already fired, and heating it’s surface to melting temperature might make the results black.

I’d suggest you use of Laser Tools → Materials Test to try and dial in the proper speed/feeds. Some material may never be lased to black… such is life.

Slate … some turns white, some dark…

Good luck


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Oh I’ve been running material tests like a mad man for a few days lol.

Basic red brick/pavers as it turns out are mostly concrete now, and just dyed on the outside. So that engraves, but is just junk white. I found basic clay bricks, but they’re porous, so the letters don’t come out super great. Fire brick has had the best results, because of the dense silica in them.

I was just trying to figure out what this guy was talking about. He was basically saying vector will cause it to engrave hotter (more intense?) than raster. But he was also using different software. From what I gather, when using text in Lightburn, that’s where the line/fill/offset come in correct? Are those considered rastering or vectoring?

Found the video::

A vector is just a line… it describes a tool path.

A fill of a vector object just adds more vectors on the inside to fill it… the number of vectors is defined by the interval (dpi/lpi).

Technically there is no real difference between vector and raster… usually raster = image are used to produce images… but they are still vector lines creating the process… what may be missing is with a raster, there could be lines where the laser isn’t turned on the whole time,

All vector/fill have the same output, normally

If you can lase through the color of the brick, it has to be applied on the surface. Most brick are made from colored concrete so they don’t have issues, such as a color change when they get chipped.

It will still boil down to if the material will produce what you want by laser heating.

They are using a specific type of brick that turns the material black when you lase it.

The Trotek people use bricks (they supply them from their store) and when it’s lased, the clay melts that results in the black color.


I appreciate that description, thank you.
Well, I’ll call the bricks good for now, aside from maybe trying to tighten up on speed vs power. Might see what speed I can get to if I turn it up to 70%.

Next I’ll move on to slate, and figure it out all over again. All my numbers from my 20w diode are useless now lol.

I doubt Trotek uses a specifically formulated brick… You might go to the order site and see if there is any information that would allow you to make selection of a brick easier from elsewhere.

The other option is home depot or something similar and pick up a few and test them.

It’s what it’s made out of… the first photo I posted was a rock from my back yard… this is clearly melted and I believe volcanic.


After watching the trotec video, I think you should use lightburn’s “ offset fill “ mode at 500 dpi 100% power and 100 mm/s. And they ran it twice.

Oh I’ve been all over locally, even a masonry supplier. Unfortunately, it Seems that most things are made of concrete now. And this it’s hard to find clay based bricks/pavers. And even then, they aren’t good quality. I’ve decided to go with the firebricks. I also got in contact with the guy from they make stuff specifically for engraving. Unfortunately, shipping costs are outrageous.

I’ll have to look at my material tests again to see if over gone down to 100 or not. But I have ran at 450-500 dpi, and I tried offset fill. I’m not a fan of how it looks. It shaved off about 8 minutes, but it didn’t necessarily make it darker. It does leave that distinct line pattern though, which is more apparent than just regular fill.

Unfortunately I think it probably comes down to the brick quality right now. I think the firebricks look awesome. I just did another with a person’s name and a star(half and half star). The contrast is really nice.

Sounds like you’re on the right track. I suppose you hunted the Internet for clay bricks? I lived by the border when I was a kid and they make tons of them down south… You’d think someone would import them as they have to be low cost.

Even think about making them yourself, they’ve been doing that for centuries… If you need 10k of them I get it…

We really like photos and settings…

Good luck, be looking forward to some photos, at least :grimacing:


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I’m in the northeast, clay doesn’t seem as easy to come by lol. I haven’t thought about making my own though, I may look into that.

Pics to follow:

160mm/s, 50% power, 20hz frequency, .055 line interval.

Neat… thanks for posting…

You should be able to drag and drop a photo/text/file on the reply/edit window or use the upload icon download-icon-background in the tool bar. There are a limit number of types (extensions) you can upload.

As and example a pdf file, is not allowed to upload, it’s generally renamed from xyz.pdf → xyz.pdf.txt and it will upload, thinking it’s a text file… These are type set by some administrator somewhere within Discourse software (site software)…

If a photo or movie over 4mB, it can be handled like you did for the photo.

Take care, let us know how the brick making works out.