Let me start with an apology. I am sure this topic has been to death many times over. I have read a large number of the postings but still not sure how to get the result that I want. This is my first post and I am pretty new to using a laser. I am using a Genmitsu LC-50 Plus 10w diode laser. I used Rust-Oleum Painters Touch 2X UltraCover semi-gloss to cover the white tile, one light coat in one direction followed by a light coat at 90 degrees to the first. I ran Material Test and the result is attached.
. Of course, it is hard to see easily from a photo, but I chose 1000 mm/min travel and 47% power for my engraving since this appeared to be the darkest by looking at it under a microscope. This was my second Material Test. The first only had the lower left hand corner which looked viable (1200 to 5000 mm/min and 50 to 100% power). Hence, I did the second based upon the first. In all of the videos that I have watched the results look a much darker black, which is what I would like.
Does my choice of semi-gloss have an effect? I could not get flat. It is hard to judge but what is too little or too much paint or is it a question of experience, and a lot of wasted tiles? I noted that some people have tried other material to paint the tile. Is there an option which is better than white paint with TiO2?
Hoping you can point me in the right direction to minimize the wasted tiles :). I have some gifts that I would like to make. Wherever, possible I use vector images. Haven’t tried jpg, etc… For photos, is it better to try and convert to vector, if possible, or use the photo with the features in LightBurn?
I agree. Would you be willing to retake this picture in daylight? I see a couple of reflected windows but I can’t tell which squares are microscopically lighter. To be fair though, I do see the 1500mm/min & 1400 mm/min at 20% power having a little bit of fade to them.
There’s so much variation that at your current level of success, it will be genuinely difficult to make a contribution.
The Squares look good, so Scanning offset settings seem spot-on.
This white tile technique makes a clean small black dot on a white background. There isn’t a richness of intermediate gray in the middle of the Material Test. Because vectors produce cleanly, the result from vector work here, is often a stark high-contrast ‘Graphic’ look and feel - like an advertisement or a street-sign. The small accurate dot, however is a great tool for dithering. The photo/image work can be really breathtaking but you can expect to waste a few more tiles getting everything perfect.
I have attached 3 images. The first is what I am trying to engrave and the second is my first attempt based upon the material test. The first is a hand-drawn bald eagle. I would like to make a gift for the First Nations teenage girl who drew it. The third image is a SVG vectorized version of the first. When I bring it into LightBurn it appears the colors reversed, ie. black is white and white is black, and I can’t figure out why!
The rectangular border outline will fill in the ‘Daylight’ around the eagle. When LightBurn gets to the next closed shape, it will be left alone, and the one inside that will be engraved.
Here are some unintentionally astonished looking hexagons.
The hand drawn eagle takes advantage of an unusual human trait. Our perception of light is logarithmic.
Dithering black dots on a white background is the opposite.
If you adjust the scanned image to make it darker to try to get the feather detail out of the cap, the throat or the lines in the beak you’ll loose the white lines in the body. If you brighten the image you’ll get the body detail but you’ll overexpose all the white.
Right click the image and select ‘Adjust Image’ toward the bottom.
What I’m suggesting is that you have to flatten it to work in a high contrast media.
The Grayscale setting on the left is a ‘Hard-No’. I selected Dither. Jarvis and Stucki would be good alternates and may produce something more appealing than this ‘first shot’.
Finally, the last piece of advice is don’t panic when the preview looks too dark. This tool shows every dot. When the dots are too close, they add up to something that isn’t a fair representation of what’s going to happen. Zoom in until you can see individual dots then you’ll know if you have the gamma right.
Click on the attached images for the larger originals.
Thanks to your help I have succeeded. In the end I sprayed the IPA/TiO2 mixture onto the tile (2 good coats) and let it dry overnight. I used Stucki for the dithering. Photo attached.
