Making a perfect piece of slate engraving would require an appropriate laser and a cleverly adjusted image with high contrast.
But, some tips will help you to improve your engraving to a great extent.
We have more than 5 years of engraving experience that includes the usage of more than 35 laser machines.
Based on our experience, we prepared a small checklist for you to improve your engraving experience with slate and stone.
Use a fiber laser
We are not truly against the CO2 laser since they work fine with slate and stone. But, if you have access to any fiber laser then you should try it.
When it comes to engraving on slate, a fiber laser usually has the edge over a CO2 laser, and here’s why:
First off, fiber lasers are great for working with harder materials, and slate is pretty tough stuff. Think of a fiber laser as a fine, sharp chisel—it can make really clear, precise marks on the slate, which is perfect for detailed designs.
In contrast, CO2 lasers are more like a broad paintbrush. They’re brilliant for softer materials and are often used for things like wood or plastic. But on hard slate, they don’t give you the same crispness that a fiber laser can.
These are the top 5 lasers for slate
we wrote after thorough experiments
Slate would require a powerful laser to bring the photo with appropriate brightness and contrast. Spare a minute at our top-ranked laser machines.
Also, fiber lasers are super efficient. They use less power and have a longer lifespan, which means you can keep engraving without as many breaks for maintenance or repairs. It’s like having a car that gets great mileage and doesn’t need a tune-up as often.
Lastly, fiber lasers are just faster when it comes to slate. They can zip through the engraving process quicker than CO2 lasers, letting you produce more work in less time. It’s a bit like racing on a bike with gears tuned for speed—you’ll finish the race quicker and with less effort.
Adjust the image for slate
We have a separate article on adjusting images that includes a detailed step-by-step approach.
Here’s a quick summary:
For top-notch slate engraving:
- Pick a Simple, High-Contrast Image: Detailed pics don’t work well. Use clear subjects with contrasting backgrounds, like a dark-coated dog against a light background.
- Photoshop for Contrast Adjustment: Duplicate your image layer, then bump up the contrast using the ‘Brightness/Contrast’ sliders.
- Grayscale It: Convert to black and white in Photoshop to simplify and focus on details.
- Sharpen Up: Use the ‘Sharpen’ filter to make details pop, but don’t overdo it.
- Dither for Depth: In your engraving software, choose a dithering option to mimic shading with dots.
- Background Begone: Use tools like ‘Magic Wand’ in Photoshop to remove busy backgrounds and highlight your subject.
- Inversion Option: Invert colors if necessary, so darks and lights engrave correctly.
- Lightburn Settings: For slate, try starting with a power above 60%, a speed of 250 mm/second, and at least 300 DPI.
- Finish with Oil: After engraving, machine oil can enhance contrast.
And remember, always adjust settings based on your specific laser machine.
Choose the perfect engraving technique
Raster engraving is the perfect fit for slate engraving, kind of like how a glove fits your hand. Why? Well, it comes down to how raster engraving works—it’s all about dots!
Imagine you’re drawing with a bunch of dots instead of lines. When you want to make a darker area, you put a bunch of dots close together. For lighter areas, you spread them out. That’s what raster engraving does; it uses tons of little dots to create an image or text.
Slate, with its natural, uneven texture, really gets along with this dot method. The laser zaps across the slate, dot by dot, line by line, just like an inkjet printer going back and forth on paper. This way, it can handle the highs and lows of the slate’s surface pretty well, making sure the image comes out nice and even.
Let’s say you’ve got a picture of a leaf. The laser will engrave all the tiny details of the leaf onto the slate, dot by dot. The result? That leaf will look super crisp, with all its veins and edges well-defined. And because the slate has that dark, moody vibe, when you engrave on it, the image pops out with a nice contrast, kind of like white chalk on a blackboard.
So, raster engraving and slate make a great team. The dot-based approach of raster engraving matches the rugged personality of slate, resulting in artwork that stands out with clear details and contrast.
Focus on the line interval
When you’re laser engraving slate, the line interval setting is super important. Think of it as setting up rows in a garden. If the rows are too close together, your plants might not have enough room to grow. But if they’re too far apart, you’ll have lots of space and your garden won’t look as full.
With slate engraving, if you set the line interval too close, the laser lines might overlap, making the design too dark or even causing chipping. If it’s too far apart, you’ll end up with gaps in your design, like missing teeth in a comb, and the image won’t look solid.
The sweet spot for slate is typically a line interval of around 0.1 mm. This is thin enough so the rows of the design are close without stepping on each other’s toes, but not so close that they smudge together. When you set the line interval at 0.1 mm, imagine drawing lines with a fine pen on paper, each line as thin as a strand of hair, with just a hair’s breadth space between them. That way, when you stand back, the lines blend into a smooth, detailed picture.
After you’ve finished engraving on a slate, giving it a bit of TLC can make your design stand out. Here’s how to do it:
- Clean Up: Engraving can leave dust and tiny slate bits on your masterpiece. So, grab a soft brush or a blast of air to gently sweep away the debris. It’s like dusting off your shoes after a sandy walk on the beach.
- Wipe Down: Next, you’ll want to use a damp cloth to wipe the slate clean. Just a bit of water will do—no need for harsh chemicals. Wipe it like you’re cleaning a pair of glasses, gently and carefully.
- Dry It Off: Let the slate air dry or pat it down with a dry, lint-free cloth. You want it bone-dry, like a sunbaked sidewalk in the summer.
- Seal the Deal: Some folks like to seal their slate to protect the design. A clear, matte finish sealer does the job without being too shiny. Spray it on like you’re applying a light mist of hairspray—just enough to cover it, not drench it.
- Oil for Contrast: Here’s a pro tip—rub in some mineral oil to make the design pop. It’s like putting on sunglasses; everything looks more vivid. Just a dab on a cloth, rub it in, and boom, your engraving will stand out with a deeper contrast.
- Buff to Shine: After the oil, give the slate a good buff with a clean cloth. It’s like polishing an apple before you take a bite, making it shine.
These steps should give your slate engraving a clean, professional look, with a contrast that makes your design sing. It’s like putting the cherry on top of a sundae—just that last finishing touch that takes it from good to great.
Overall, engraving slate would require your skills in image optimization and laser settings adjustment. Altogether, you can ensure the best result.