Agate engrave

Hi! New user here. I’m having success on some basic wood, acrylic and stone engraves. Had this on hand, thought I’d give it a try. I believe it’s agate, but I could be mistaken. I taped off shiny areas, not sure if they’d reflect/damage laser.

Settings: 800 sp/ 90 power/ 270 LPI /single pass.

As you can see, a bit of flaking off, which I’ve seen happen on some stones. Lines are noticeable to me close up. From a distance, as if a pendant on a necklace, actually looks nice. “Defects” in engrave actually look like natural w/stone. Not too bad, anyway, but i can see might not be to someone’s taste.

Any suggestions for better settings?


Additional image


That is beautiful, and very fresh and clean looking. The colours really work here.


Generally I’ve found the flaking is a sign that you lasered a bit too much laser.

Try dropping power or upping speed a bit and see if you get good whites without the spalling.


Thanks. Will give that a try!

1000 sp/ 60 power/ 270 LPI/ 1 pass

Close up, I can see the lines. From a distance though, this engraving looks smoother.


I’m going to try more settings later, but had a thought on this. Would “defocusing” help out, maybe? Honestly, I need to look that up and figure it out. I’m working on getting cleaner engraves on other materials, too, fewer lines overall. I can up the LPI, but am thinking that might overwork the stone, too. Practice, practice, practice…

Definitely worth giving defocusing a shot - basically either add or subtract 1/2" from your actual height in the steps on the left hand side.
That way you can still use Set Focus to get your piece lined up with the art, but the laser will use the individual focus set into the steps.


That is beautiful


Looking at the close-up (nice pic), I would think a combination of increasing the LPI, reducing power accordingly, and defocusing, would help.

This is exactly what happens when you engrave on acrylic. Several threads exist on how to “smooth out” engravings on clear intended to be edge-lit.

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Oh, that’s how you do it!

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I just did a run on 8 different color agate slices from the same vendor. Some are so perfect it looks like I put a sticker on it, others look just fine and a couple look like my machine doesn’t work very well. Light pink, light lavender, light gray/white and light blue are a definite no go, though the darker areas towards the edges are just fine. So if I were to purchase those colors again, I’d definitely stick to the perimeter for the gf and away from the nucleus. The darker colors look amazing throughout the entire surface. I used the settings above that @deirdrebeth posted.

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FYI those settings were only posted so I could show them where you adjust height to defocus an engrave. Those are the SD Graphic PG settings for leather (cuz that’s what I was working on at the time)…that they worked on your agate is pure happenstance!