10 Laser Engraving Terms You Must Know

One of the things you will quickly realise if you have just bought a laser engraver, or are thinking about getting into the laser engraving business here in Canada, is that people throw around a lot of technical terms. DPI, PPI, vector, dithering… it can feel like a different language at first.

But it is important—not only to know what these terms mean, but also how they can help you on your journey to mastering laser engraving. In truth, these are terms that describe processes or settings that can help you fix problems faster, get cleaner engravings, avoid wasting expensive materials (like Canadian Maple or Walnut), and work more confidently and efficiently.

Think of it like cooking. Even if you are not a professional chef, you still need to know what “medium heat” means if you want consistent results with your recipes.

1. DPI (Dots Per Inch)

DPI in laser engraving stands for “dots per inch,” and it refers to how many dots (or pixels) are engraved per inch on the material. DPI directly affects how much detail your engraving produces, and it also controls the amount of overlap you will get between the engraved dots.

DPI is one of the more technical details of laser engraving, and it usually takes some time and practice to master because it is not always straightforward. You cannot just set a high DPI and start engraving: you have to deliberately choose the appropriate DPI based on the specific material you are working with.

For example, if you’re engraving a photo on acrylic, increasing the DPI can make the image sharper. But if you go too high, you may end up with a cloudy or overburned look instead of crisp detail.

As a rule:

• Wood engraving often looks better at lower DPI (it prevents overburn and deep charring).

• For acrylic engraving, you need moderate DPI for a clean frosted look. Too high, and you’re just re-burning the same area without gaining detail.

You have to pay strict attention to DPI when you are engraving photos or detailed artwork, working on acrylic, glass, or coated metals where clarity matters, or when adjusting your machine settings to find the right balance between production speed and quality.

2. PPI (Pulses Per Inch)

PPI in engraving stands for “Pulse Per Inch”, and it refers to how many laser pulses are fired per inch of movement. It essentially determines how continuous or “connected” your laser output is. It affects whether your cuts will be smooth or dotted, and whether engraving will look consistent or uneven.

A practical way to understand PPI is to think of it as the setting that controls how “solid” your laser line will be.

• Low PPI gives a more disconnected, perforated effect (perfect for fold lines in cardstock).

• High PPI gives smoother, cleaner cuts.

Laser cutting acrylic with low PPI might leave rough, jagged edges. For smoother cuts, you have to increase the PPI. But keep in mind that there is a risk of melting or excessive residue when the PPI is too high. You mostly deal with PPI when laser cutting, especially if you are working with materials like acrylic or plywood.

3. Line Density

Line density in laser engraving refers to how closely the engraving lines are spaced together. It is closely tied to DPI, and it controls how “filled-in” your engraving looks.

If your engraving looks like a series of parallel lines instead of a solid fill, this is the setting you adjust first. Your line density is probably too low, and increasing it will fill in the gaps for a smoother finish. This is especially important when:

• Engraving logos, filled text, or solid shapes.

• Trying to eliminate visible scan lines.

• Adjusting for material response (e.g., how soft Birch ply reacts vs. a hard Oak).

4. Air Assist

Air assist in laser engraving is the stream of compressed air directed at the laser point during engraving or cutting. The two main roles of the air assist system are to blow residue away (so it doesn't stick to the lens or the work) and to reduce burning and flare-ups.

In any Canadian workshop, air assist is a massive deal because it has a huge impact on the quality of the final product. If your engravings look dirty, soot-stained, or burned, the issue often is a lack of airflow.

• For wood engraving, air assist minimises charring.

• For acrylic, it minimises residue buildup.

Engraving wood without air assist often leaves heavy charring and soot. Turn it on, and suddenly your engraving looks cleaner and more professional. It is one of the easiest ways to instantly improve engraving quality.

5. Dithering

Dithering is a technique that uses patterns of dots to simulate shading in images. Since the laser essentially burns in one tone (on or off), dithering is essential for engraving photos or grayscale images. It turns a flat image into something that looks like it has depth and shading.

This explains why dithering is so important in portrait engraving: it determines how smooth the shading looks. Different dithering patterns (like Jarvis or Floyd-Steinberg) can dramatically change the final image. Mastering this is a must if you plan to do photo engraving or work with grayscale graphics.

6. Dot Duration

In laser engraving, dot duration is how long the laser stays on for each individual dot. The dot duration controls how deep and dark your engraving will appear, but at a micro level.

Instead of cranking up the power (which can get messy), you can make subtle improvements by adjusting the dot duration to change how much energy is applied at each point. No need to change your overall speed or power settings. It is particularly useful when:

• Fine-tuning photo engravings.

• Adjusting darkness without overburning sensitive materials.

7. Vector

In laser engraving, “vector” refers to a type of laser file or engraving method that is based on paths (lines and curves), as opposed to pixels. Laser cutting and clean line engraving are always done in vector format: vector paths tell the laser exactly where to go with absolute precision.

You use the vector format when:

• Cutting shapes out of material (like 3mm Birch ply).

• Engraving text outlines or sharp borders.

• Creating logos with crisp edges.

Practical insight: if you want sharp edges, you use vector. Raster will never give you that same level of precision for outlines.

8. Raster Engraving

"Raster" in laser engraving means engraving line-by-line, much like how a standard inkjet printer works. Raster is slower than vector, but it is better if you want greater detail: it fills areas better and engraves complex designs.

Raster engraving is what you go for when engraving images, photos, or filled graphics. If you’re engraving a photograph onto wood or acrylic, you are using raster mode, not vector. Most professional projects use a mix of both: Raster for fills and images, while Vector for outlines and cuts.

9. Power (%)

The power of a laser engraver is a measure of the intensity of its laser output. This matters because it determines how deep or dark the engraving is.

• Too much power on acrylic can cause melting or fogging.

• Too little power might not mark the surface at all.

The “typical power” required varies a lot depending on the type of laser (Diode, CO2, Fibre) and whether you’re talking about hobby use or small business production.

Typical Laser Power for Different Laser Engravers

10. Speed

Laser engraving speed refers to how fast the laser head moves. Speed is one of the most important settings because it (together with power) determines the depth of your engraving through "exposure time."

• The slower the speed, the deeper the engraving (more exposure).

• The faster the speed, the lighter the engraving (less exposure).

If your engraving is too dark, increasing speed can often lighten it without having to change your power settings.

Reference Table: Laser Engraving Glossary

Explore Beginner-Friendly Laser Engravers

A 60W laser engraver is often considered the ideal entry-level option for small Canadian businesses. It is affordable and powerful enough for engraving wood, acrylic, leather, and glass—the staple materials for most startups.

With a rated power of 60W, the OMTECH Pronto 35 is the ideal laser engraver for a beginner looking to enter the business. It engraves at a maximum recommended speed of 800 mm/s, comes with a large 20-inch x 28-inch workspace, extensive software compatibility (Lightburn, RDworks, etc.), and a laser Class 1 safety level.

Equipped with an autofocus function and a wide workspace, this machine helps you build foundational skills while meeting the demands of a growing business in the Canadian market.

Final Thoughts

Learning these terms isn’t just about memorising definitions; it’s about understanding how your machine behaves. Once you get comfortable with them, something clicks: you stop guessing, you start adjusting with purpose, and your results become more consistent.

And that’s when laser engraving really starts to feel less like trial-and-error, and more like a skill you actually control. If you’re serious about your craft, don’t skip this step. These terms are the foundation, and once you know them, everything else gets easier.