Horizontal lines on slate engraving

[danielle.r.richards]

I just entered the world of engraving slate and am having issues with getting a “perfect” image engraved (see pictures). Has anyone else also ran into horizontal lines showing up across their engraving and know how to solve it?

Settings
Power: 30
Speed: 905
LPI: 270

[GrooveStranger]

I have seen banding like that before. It went away when I changed LPI settings. I never looked into it more. Try taking your LPI up one notch.

You can also do multiple tests on one piece, no need to run the whole thing if you see it going bad!

[evansd2]

@GrooveStranger may be right, though it looks like it may be variation in the material to me. If I were testing I’d up the power significantly, at least double. If it still happens then you’d know for sure.

You might like this:

Settings for Engraving on Slate

Ok my addition to slate settings: this was done at 900/30/225. Vary power, one pass, minimum power zero. On slate prep: Thanks to @kittski, I wiped the board down with mineral oil first – it doesn’t require much oil, go light, and use the most lint-free rag you can wrangle. If you’re desperate, paper towels will work, but paper bits get stuck all over the place. Then, expanding on her idea, I let the oil soak in for about 5 minutes, then washed the board thoroughly with dish soap and water. …

The oil trick is really nice with slate.

Also, you can sand slate smooth and reuse it in a pinch. Might be useful if you are running low on test material.

[danielle.r.richards]

I ran a few more test on one coaster and upped the LPI and that helped a little but still getting lines. I will try upping the power next.

[GrooveStranger]

Interesting… Please keep us posted. Good luck!