Photo engraving granite using Corel and VLS6.60

[Keith Colson]

I wasted half of my day playing with granite today. A customer is threatening to come in this week for some granite photo engraving. I finally got it sorted using Corel Draw and my Universal laser cutter. I ended up with 100% power and 50% speed with my 60 watts. It took 30 minutes to engrave a 300x300mm granite tile at density 3. It was the cheap kind of tile with lots of flecks in it. I am sure a super black tile would have been much easier but they are very expensive here.

Here are a couple of pictures. As usual I am keen on constructive feedback The big question I have is what is the durability of these engraved granite tiles? Will they damage, fade and wear? Do I need to protect it with a coating etc.

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And zoomed in to see the detail of the image processing
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Cheers
Keith

[Bernie Fraser]

Keith that seems to be a lot more power for granite than I use, but I am still only learning myself. My default with a Rayjet 30 Watt is power 30 speed 50.I even found that sometimes the photo looked better if I dropped the power down to 20. I found if I used too high power detail was lost. Same if I used high dpi to engrave. 333 looked better than 600 dpi. Granite will not fade or be effected by rain so it is great for outdoors. Unsure if it needs a coating for protection. The thing that you have going for your current setting is that it is easy to distinguish the image.

[Dan Hintz]

I ended up with 100% power and 50% speed with my 60 watts

Did you reverse those settings by mistake? That's WAY more power than you should need to use...

[Keith Colson]

Hi Guys

Yes, you are right the power is much higher but there is a reason behind that. My image has a 10% black density with large contrast radius. This gave me a much brighter sharper image than I was able to obtain with other methods I tried.

I can engrave at less than half the power with an image density of 20% or more but I cannot get the bright white and sharp contrast using that method. The granite I have tends to make a large spot if I want it bright so I compensated for that with a large contrast radius and a low density image

I would attach the file but it is too big. If you have any Corel test files for granite I am keen to see how you have set them up.

Cheers
Keith