Rock coasters have become more common in households today, not only because of their aesthetic appeal, but also because slate is a readily available stone. Don’t have a plain boring coaster sitting in your kitchen when you can personalize it by engraving a beautiful design on it. All you need to do is come up with the design (names, logos, images, or patterns) on a software, and the laser engraving machine does the rest.

If you are new to laser engraving, I will cover everything you need to know, all the beginner-friendly steps to follow, and answer the most frequently asked questions around this topic.

Optional Materials 

With everything for the project ready, let's start engraving on the rock coasters.

The rock should be flat and smooth-surfaced. If that's the case, proceed directly to the cleaning section. Machine-cut rocks are more preferable due to their consistency, which makes them easier to work with.

The best rock size to use is 10cm x 10cm with at least 5mm thickness, as it is compatible with most engravers’ laser beds. Check for chips, cracks, or texture differences, especially on the area you want to engrave on. Use shims or a jig to level the coaster uniformly.

Sand rough surfaces, then wash using warm water and soap. Equally, use a microfibre cloth with rubbing alcohol to remove oils and dust.

This is where you go all out on your creativity to make your coaster stand out. You need design software such as Adobe Illustrator, CorelDRAW, or Canva. When designing, stick to bold lines, high contrast texts, and solid shapes.

Keep the design within a 9cm x 9cm working space, but size it according to your project. Always leave a small margin along the borders so that nothing is cut off or masked when engraving.

To engrave photos or artwork, use raster images with a high resolution of at least 300 DPI. This helps the laser engraver convert shades of grey or color into different laser intensities for a much clearer image.

After the design is ready, convert it to a vector format, and convert any text to outlines or paths to avoid font compatibility issues. It keeps all the fonts the same on any machine, helping the laser engraver interpret it correctly.

Remember to save copies of the design’s original copy and the converted format separately, in case you would like to make some changes later, especially if it has editable text.

Plug the laser engraver into a power source and turn it on. Flip the power switch and safety lock. Allow the engraver to complete any automatic start-up calibration. Disengage the emergency button for safety.

Pressing the “Home” button automatically moves the laser head to a start position. The display screen might read “ready”, and the LED lights on the laser module turn on, to show that you can set up the design software and start engraving.

This helps you send files and engraving commands directly to the engraver from the computer. You can either use a USB cable, WiFi, Bluetooth, or cloud-based apps, depending on the model.

If using a wireless method, use your computer to scan for the engraver using its name or IP address.

On the design software, you will go through steps to find the laser, connect manually, then confirm the working area dimensions and device name before sending the design for engraving.

If the computer is unable to detect the engraver, check your wifi connection, the USB cable connections, or restart both your computer and engraver.

Centre the rock on the laser bed and ensure it is flat and stable, or at least with its flattest side facing up. To prevent it from shifting mid-engraving, secure the edges with painter's tape or magnets if the machine has a magnetic bed. Double-check to ensure that the center of the coaster matches that of the laser bed before securing it.

Most engravers require manual focusing, either using the focus gauge or adjusting the beam until it is sharp.

The screen of the design software will automatically show controls or the bed preview, where you can adjust the power and speed settings for cutting. The right laser settings will help you avoid burning, under-engraving, or chipping the rock. While at it, adjust the design's contrast, sharpness, and depth.

Here are the recommended laser settings for different rock coasters.

Use an extra coaster to perform an engraving test. Send the design from the computer to the engraver and press the “Start” or “Engrave” button. As it engraves, check for signs of excessive smoke, under markings, or scorching.

The best engraving settings should result in deep, sharp lines with contrast in the engraved areas and clean edges. Record the settings with the best results and use them to engrave on the main coasters.

Calibrate the laser engraver with the speed and power settings recorded from the previous step.

Use the “Frame” or “Preview” button to double-check the design placement. This moves the laser beam along the edges of the outline without firing.

Press the “Start” or “Engrave” button to start engraving the different layers of your design. Do not leave the machine unattended. Keep a close eye for fires or mechanical issues, and press the emergency button in case it happens.

After engraving is complete, wait for the rock to cool down before removing it from the laser bed. Wipe away the debris or dust using a soft brush or lightly rinse it with water.

The coaster is now complete, but you can add some finishing touches to improve its aesthetics and make it more durable.

Use a fine brush to dab acrylic paint on the coaster, then wipe away the excess before it dries up. The type of paint used should be compatible with the rock. The best to use are acrylic paint, oil-based markers, and enamel paint. You can also transfer some designs, such as letters and detailed colored designs, onto the coaster using quality transfer paper. This should, however, be done before painting.

Spray a light, even coat of clear acrylic spray sealant to protect the engraving from dust, water, and fading. It also helps add richness to the colors and preserve the added paint. The sealant also helps prevent staining by blocking spillages from seeping into the stone.

To prevent the coasters from scratching tabletops, glue rubber or felt pads on the bottom side. This also helps the coaster have a good grip on smooth surfaces. For other customization methods, you can apply printable vinyl designs to your stone coasters using a heat press machine. 

To preserve the rock coasters and maintain their appearance, try these maintenance methods.

Regular cleaning

Use a damp cloth and lightly scrub the surface to get rid of dust and spills. Avoid abrasive scrubbing and rubbing, as it might dull the engraved design. If the water does not bead up on the surface, it requires resealing.

Enhance the Engraving

Reseal the coaster occasionally, or whenever the engraved surface starts looking dull, or water starts seeping through. If you used a paint fill, repaint the coaster before resealing.

Preventing Damage on the Coaster

Avoid sudden extreme temperature changes on the coasters; it might lead to cracking, especially on thin rock. However, most rock coasters can handle hot mugs, but avoid placing piping hot pans or frozen items directly on them.