Understanding DPI for Better Laser Engraving Results

If you're new to laser engraving, you’ve probably come across the term DPI—short for dots per inch. It may seem like just another technical setting, but it plays a big role in determining the clarity and quality of your final engravings.

In this guide, we’ll explain what DPI really means in the context of laser engraving, how it interacts with different materials, and how to pick the right settings for your projects. Whether you're engraving wood, glass, or another surface, understanding DPI will help you achieve cleaner, faster, and more accurate results.

What Does DPI Mean in Laser Engraving?

In printing, DPI refers to how many dots fit into one inch of space. In laser engraving, it works a little differently—it refers to how many lines your laser creates vertically in a single inch as it moves across the material.

This value affects how tightly packed each engraving pass is. Higher DPI means the lines are closer together, producing finer detail but taking more time and generating more heat.

Think of DPI as Your Vertical Resolution

Just like a higher-resolution image has more detail, increasing your DPI gives your laser engraver the ability to create sharper, more intricate engravings—especially for photographs and complex artwork.

But higher isn’t always better. The ideal DPI depends on the material you're working with and the level of detail you want to achieve.

DPI and Wood: Go Easy for Better Results

When engraving wood, you're essentially burning the surface. Because wood is porous and organic, excessive heat or overlapping lines can cause the engraving to look muddy or overly dark.

That’s why lower to moderate DPI values often yield the best results on wood. When lines are too close together, they can bleed into each other and ruin the clarity.

Best Practice:
Use a DPI that’s high enough to show detail, but low enough to avoid excessive overlap. Always test a few different settings on scrap wood to find the sweet spot.

DPI and Glass: Precision is Key

Engraving on glass is very different from wood. Instead of burning, the laser creates tiny fractures on the surface by heating and cooling it rapidly. These micro-cracks scatter light and give glass engravings their frosted look.

The problem is, glass is very sensitive to heat. Too much DPI can cause unwanted cracking or distortion. In this case, balance DPI with proper speed and power to avoid damaging the material.

Best Practice:
Run a material test that varies speed and power to see how your specific glass reacts. Once those settings are dialed in, choose the lowest DPI that still looks good to reduce risk and speed up the job.

General DPI Recommendations

There’s no universal "best" DPI—it depends on your material and your design. But these general guidelines can help:

• 100–150 DPI: Good for engraving on wood, leather, or designs with minimal detail
  

• 200–300 DPI: A solid middle ground for most jobs
  

• 400–600 DPI: Best for engraving photos or intricate graphics on heat-tolerant materials
  

• Above 600 DPI: Usually unnecessary; may cause overheating or blurred results

Example: At a line interval of 0.1 mm, you're engraving at roughly 254 DPI. Shrinking the interval to 0.07 mm increases resolution but slows the process.

DPI, Speed, and Power: How They Work Together

DPI doesn't work in isolation—it must be balanced with laser speed and power. A lower DPI paired with higher speed might produce better results than a high DPI with too much heat.

For instance:

• At 200 DPI, 30% power, and 150 mm/s on glass = clean frost
  

• At 400 DPI, 40% power, and 100 mm/s = excessive cracking and fogginess

Tip: Always run small test engravings before committing to your final design.

What About Line Interval?

In software like LightBurn, DPI is often represented by line interval—the distance between engraving passes (in millimeters). The smaller the interval, the higher the DPI.

Here’s a quick conversion chart:

Understanding how line interval affects DPI is key to fine-tuning your settings.

Final Thoughts: Test, Tweak, and Learn

Laser engraving is as much experimentation as it is technique. The best way to learn how DPI affects your results is to engrave the same design at multiple DPI settings, observe the results, and refine them based on your material and project goals.

Ready to Get Precise?

OMTech’s line of CO₂ laser machines work seamlessly with LightBurn and give you complete control over DPI, speed, and power settings. Whether you’re working with wood, glass, acrylic, or metal, OMTech lets you engrave with clarity, accuracy, and confidence.

Explore OMTech laser engravers today and unlock your full creative potential.