How DPI Impacts Your Laser Engraving Results

If you’ve recently started laser engraving, chances are you’ve seen the term DPI tossed around in tutorials or your laser software. DPI—short for dots per inch—might seem like a minor detail, but it plays a major role in how your final engraving turns out.

From intricate wooden patterns to frosted glass designs, understanding how DPI works helps you get the detail you want without slowing down your job or damaging your material. In this article, we’ll break down what DPI really is in the context of laser engraving, how it impacts different materials, and how to find the right setting for your needs.

DPI Explained for Laser Engraving

While DPI in printing typically refers to how many ink dots are placed in an inch, in laser engraving, it’s more about how many horizontal engraving lines your machine passes through in a vertical inch of space.

This means the higher the DPI, the tighter and more frequent your laser passes will be. Higher DPI generally results in finer detail—but it also increases job time and heat buildup.

Think of DPI Like Resolution

You can think of DPI as the laser equivalent of screen resolution. Higher resolution (or DPI) gives you more detailed images—but also puts more strain on your system. With laser engraving, more lines mean more time and more energy applied to the material, which isn’t always a good thing.

The trick is finding the lowest DPI that still gives you the detail you need.

How DPI Affects Wood: Avoid Overkill

Wood reacts to the laser’s heat by burning the surface. Since it’s a natural and porous material, excessive heat can cause wider burns than intended. When DPI is too high, the lines become so close that they overlap, darken the design, and reduce clarity.

Recommendation:
Stick to a moderate DPI—enough to show detail, but not so high that lines bleed into one another. Always do a test run on a sample piece first.

DPI and Glass: Detail with Caution

Glass reacts differently. Rather than burning, it fractures slightly when hit with the laser, creating that frosted white effect. But glass is sensitive: too much heat can cause cracking or rough, scattered engravings.

This makes it important to pair DPI with balanced speed and power settings.

Recommendation:
Start with a power/speed test grid to see how your glass reacts. Then, increase DPI only as needed to achieve clean, clear detail.

General DPI Guidelines by Material

There's no universal DPI that works for everything. But here’s a rough guide based on materials and use cases:

• 100–150 DPI: Good for wood, leather, and designs where detail isn’t critical
  

• 200–300 DPI: Best for general use—balance of detail and speed
  

• 400–600 DPI: For photo engraving and very fine designs (use only on heat-tolerant materials)
  

• Above 600 DPI: Rarely needed; often causes overheating or blurring

Note: Reducing your line interval in millimeters will increase effective DPI. For example, a 0.1 mm interval equals roughly 254 DPI.

Balancing DPI with Speed and Power

DPI doesn't work alone—how it performs depends on your machine's speed and power settings. A high DPI with too much power can burn or damage your material, while a lower DPI with proper speed can deliver better results in less time.

Example: Glass Engraving

• 200 DPI, 30% power, 150 mm/s = crisp frost
  

• 400 DPI, 40% power, 100 mm/s = hazy edges, cracking

This is why material testing is so important. Try various combinations on scrap before engraving your final design.

What is Line Interval in LightBurn

If you're using LightBurn, you may notice that DPI is sometimes referred to as line interval—the distance between each horizontal pass, measured in millimeters.

Here’s how line interval correlates with DPI:

The smaller the interval, the higher the DPI—and the more detail you’ll get (along with longer engraving times).

Final Thoughts: DPI Is a Tool, Not a Rule

Laser engraving is a balance of detail, speed, and material response. Instead of defaulting to the highest DPI possible, aim for the lowest DPI that still meets your quality needs. That approach saves you time, reduces material stress, and delivers cleaner results.

Don’t be afraid to experiment. Test the same design at multiple DPI levels, compare the outcome, and use that insight to fine-tune your future projects.

Why Choose OMTech?

OMTech CO₂ laser machines give you full control over DPI, speed, power, and line interval settings. Whether you're working on wood, glass, metal, or acrylic, OMTech engravers are designed to help makers and professionals achieve the precision their work demands.

Explore OMTech laser machines today and engrave with confidence, clarity, and full creative control.