When engraving slate coasters with a laser, achieving the right settings is crucial for optimal results. It is generally recommended to use a CO2 laser with a power range of 30-50 watts for this task. The speed settings should typically be set between 200-300 mm/s, which helps prevent overheating and ensures a clean engraving.

For the best results, start with a lower power setting, around 20-30%, and gradually increase it if necessary. This allows you to find the sweet spot for engraving without damaging the slate. A focus lens with a focal length of around 2.5 inches is recommended to enhance detail and precision.

Additionally, consider using a raster engraving mode for intricate designs, as it creates a more detailed finish. It’s also beneficial to conduct a test run on a scrap piece of slate to fine-tune your settings based on your design complexity and the slate’s thickness.

Lastly, proper ventilation is essential to remove smoke and debris created during engraving, ensuring a clean workspace and high-quality results.