E.T. go home and have a nice cup of tea

I was inspired by Jule’s post on multi-tone slate drawing. My attempts took way too much effort to get the balance right, but I got there in the end.

One colour looks great and is easy to do (following Jule).


Then I decided to try for a full tone range plus un-burned regions for contrast. These round slates are around $1 each from Amazon, so I could afford to experiment, which was lucky - it took me around 4 coasters before I got the image and the GF settings right.

The shape and texture of the raw material lends itself to spooky or space themes. Here’s a movie I love…

The media was prepared from publicly available posters as well as high quality moon pictures from NASA. I put them together in Affinity Photo for Mac, my final version had like 25 layers (most of which I could probably remove now). The bike and the tree silhouette is 100% white - meaning the laser doesn’t touch that part at all. I didn’t reproduce the full range of contrast in the end - the big crater at the bottom (nearly full black) doesn’t really appear. I think it still works.

Lessons I learned

The Material

  • slate is slightly shiny, the engraving isn’t visible from all angles.
  • the engraving seems quite durable
  • getting it wet or greasy can decrease contrast temporarily
  • there are little shiny specks which make it extra awesome.

Media Preparation

  • alpha in images can cause unexpected noise in the output that you can’t see in previews. I recommend to remove alpha blending to make sure you can see what will be rendered.

Burn considerations

  • full white parts of the image (no burn) must not contain compression artefacts or noise - this will ruin the super contrast you get between burned and non burned part of the image. Avoid jpg (and alpha).
  • it’s a good idea to burn a gradient at different powers on a scrap of the same material (e.g. the back of the coaster). This will help you calibrate.

p.s. The shards are from a penrose puzzle I made one time. I’ll write about that one time.

The ET over the moon is an exceptional result!


Love E.T.!

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Wow, amazing engraving! Thanks for all the insights.

Really wonderful!

Loved the ET as well! Well done! Just finishing a Cheese Board engrave in a Slate as well. image


Remember there are two sides to each slate coaster when experimenting with settings. :slightly_smiling_face:

Also if you wipe it with mineral oil & let dry you get more contrast.

Finally, if you’re hardcore in reusing them, use some 220 or 320 grit sandpaper to get back to a uniform surface, re-mineral oil and re-engrave.


Stupid question – would that wipe down be BEFORE or AFTER engraving?


Inside the sausage factory:


Problems with noise:


Those are great! (That was one of my favorite movies!) :grinning:

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Before. Otherwise you’ll find your engrave disappears :slightly_smiling_face:

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Awesome results! I had been working on some slate coasters I found at a craft store. It came out great except that there was a lip in the stone I didnt see. I suppose sanding it down before printing could have prevented it. Still pretty awesome. Do you remember what settings you ended up using?