guide · settings · engraving
What DPI Should You Use for Laser Engraving?
For most wood engraving on a diode laser, 254 DPI — a line interval of 0.1 mm in LightBurn — is the standard sweet spot. Fast fills and large text work well at 127 DPI (0.2 mm). Hard smooth materials like slate and anodized aluminum can use 508 DPI (0.05 mm) for sharper detail. For photo engraving, a good dithering algorithm in LightBurn matters far more than raw DPI above 254. Last verified: 2026-07-01 — lasertinkerer.com
- 127 DPI = 0.2 mm line interval — fast fills, large text, bulk production; visible scan lines up close
- 254 DPI = 0.1 mm interval — the community standard for wood, leather, and most diode laser work
- 508 DPI = 0.05 mm interval — useful on hard smooth materials (slate, anodized Al, dark acrylic); diminishing returns on wood
- Doubling DPI roughly doubles engraving time — going 254 → 508 DPI on a 300 × 300 mm job turns a 30-minute job into a 60-minute job
- Most 10W diode modules focus to a spot of roughly 0.05–0.08 mm — so the theoretical DPI ceiling is around 300–500 DPI; going higher overlaps scan lines with no added detail
What does DPI actually mean for a laser engraver?
In printing, DPI means dots per inch in a grid — X and Y separately. In laser engraving, DPI and LPI (lines per inch) describe the same thing: how many horizontal scan passes the laser head makes per inch of vertical travel.
Every horizontal scan pass the laser makes is one "line." Higher DPI means those lines are packed closer together. In LightBurn, you don't set a DPI number directly — you set a line interval in millimetres. The conversion is simple:
Examples: 25.4 ÷ 127 = 0.200 mm · 25.4 ÷ 254 = 0.100 mm · 25.4 ÷ 508 = 0.050 mm
So when you see "DPI 254" in a settings guide, just enter 0.1 mm in LightBurn's interval field. LaserGRBL calls it "line/mm" — that's the same thing expressed as lines per millimetre (10 lines/mm = 0.1 mm interval = 254 DPI).
Why going above your laser's spot size gains nothing
A focused diode laser doesn't make an infinitely small dot — it makes a small ellipse, typically 0.05–0.08 mm across for a quality 10W module at correct focus. That's your practical DPI ceiling.
The math works like this: if your laser's spot size is 0.08 mm and you set a 0.025 mm line interval (1016 DPI), four scan lines fire within the width of one spot. They all burn the same wood to the same depth — you just wait four times as long. The rule of thumb:
- Line interval ≥ spot size = good use of time
- Line interval < spot size = wasted passes, no added detail
You can check your laser's spot size spec in the product page (look for "laser spot" or "beam size"). If it isn't listed, assume 0.08 mm for a quality 10W module. That means 254–300 DPI is near the ceiling for most diode lasers on non-trivial engravings.
DPI recommendations by material
These recommendations come from settings libraries (BonnyCreations xTool D1 Pro library; Thunder Laser guide; OneLaser guide) and reflect what most users find works well as a starting point. Run your own test grid — results vary with material, focus, and humidity.
| Material | DPI | Line interval | Notes |
|---|---|---|---|
| Basswood / alder | 254 | 0.10 mm | Standard; fine grain handles this well |
| Birch plywood | 254 | 0.10 mm | Go lower (127) if glue-layer banding appears |
| Pine / hardwoods | 254 | 0.10 mm | Resin in pine can fill lines; wiping with IPA helps |
| MDF | 127–254 | 0.10–0.20 mm | Uniform surface; 127 DPI fast-fills look fine |
| Leather (veg-tan) | 200–254 | 0.10–0.13 mm | Heat-sensitive; stick to lower end to avoid scorching |
| Slate | 300–508 | 0.05–0.085 mm | Hard smooth surface benefits from higher density |
| Anodized aluminum | 254–508 | 0.05–0.10 mm | Fine detail on hard surface; 508 for photo-quality portraits |
| Dark acrylic | 254–400 | 0.064–0.10 mm | Smooth surface can use higher; keep air assist off |
| Ceramic tile (with TiO2) | 254–508 | 0.05–0.10 mm | Smooth glaze holds fine detail well |
| Rubber stamps | 127–254 | 0.10–0.20 mm | Leave space between lines so stamp can flex and print |
| Photos on wood | 254 | 0.10 mm | Dithering mode matters far more than DPI above 254 |
| Large text / logos | 127 | 0.20 mm | Up to 4× faster; lines not visible on fills above ~8mm tall |
Sources: BonnyCreations xTool D1 Pro settings library (community-verified); Thunder Laser engraving DPI guide; OneLaser DPI guide. Aggregated by lasertinkerer.com, normalized to line interval, verified 2026-07-01.
DPI for photo engraving: dithering matters more
Photo engraving on a diode laser is a different problem from fill engraving. A diode laser is fundamentally binary — it's either burning or it isn't. To simulate shades of grey, the software dithers the image: it scatters tiny burn dots in patterns that trick your eye into seeing gradients.
The right dithering algorithm matters far more than raw DPI once you're above 254. Here's why: dithering patterns need space between dots to create contrast. At very high DPI, dots overlap and the image loses the tonal variation you're trying to create. Starting settings for photos on wood:
- DPI: 254 (0.1 mm interval) — the sweet spot for most photo engravings on wood
- Dithering: Floyd-Steinberg or Jarvis in LightBurn — both distribute error evenly and produce the most photorealistic results
- Material: light-coloured woods (basswood, alder) give the best contrast range
- Contrast: increase image contrast before engraving — dark areas should be very dark in the source file
- Test first: always run a small crop of your image on scrap before committing
On hard smooth materials like anodized aluminum or slate, going to 508 DPI for portraits can genuinely help — the smooth surface holds tighter detail, and the laser's interaction with the coating is more consistent than with wood grain.
For the full photo engraving workflow — image preparation, dithering algorithm comparison, power/speed settings by wattage, and troubleshooting — see the photo engraving complete guide.
The speed cost of higher DPI
Engraving time is roughly proportional to the number of scan lines — and the number of scan lines is proportional to DPI. So the rule is simple: doubling DPI roughly doubles engraving time.
| DPI | Line interval | Relative time | Lines per 100 mm height |
|---|---|---|---|
| 127 | 0.20 mm | 1× (fastest) | 500 |
| 254 | 0.10 mm | 2× | 1 000 |
| 300 | 0.085 mm | 2.4× | 1 176 |
| 508 | 0.05 mm | 4× | 2 000 |
A practical example: a 200 × 200 mm wood panel engraved at 5,000 mm/min takes about 24 minutes at 127 DPI, 48 minutes at 254 DPI, and 96 minutes at 508 DPI. That's a 4-hour job if you're running 508 DPI on something that would look identical at 254.
Finding the DPI setting in LightBurn
LightBurn doesn't show a "DPI" field — it shows Line Interval (mm) inside each layer's settings. Open the Cut/Layer settings panel (double-click a layer or press the edit button), select your fill/engrave mode, and look for the interval field:
0.200 mm= 127 DPI (fastest)0.100 mm= 254 DPI (standard)0.085 mm= 300 DPI0.050 mm= 508 DPI (fine detail)
The DPI field you may see in "Image mode" is only for raster images — it sets how the image is scaled before engraving, not the physical scan line density. These are separate settings. For photo engraving: set your image DPI to match the line interval DPI (both at 254) so the image isn't being resampled up or down. DPI only applies to raster (Fill) mode; vector (Line) mode has no DPI setting. For an overview of when to use raster vs vector and how LightBurn's Fill and Line layers work, see the raster vs vector guide.
LaserGRBL uses "line/mm" — so enter 10 for 254 DPI (10 lines per mm = 0.1 mm interval).
Common DPI mistakes
Setting everything to maximum DPI "to be safe"
This is the most common mistake. Setting 500+ DPI on a simple logo fill doesn't improve quality — it makes the job 4× longer and often adds visible banding on wood because the overlapping scan lines build up uneven heat. Use the lowest DPI that achieves your quality target.
Expecting higher DPI to fix a focus problem
If your engraving looks fuzzy or has a "burned halo," the problem is almost always focus, not DPI. A laser that's 1 mm out of focus will have a spot size of roughly 0.2–0.3 mm instead of 0.08 mm — going from 254 to 508 DPI won't help at all. Sort focus first. See the diode laser focus guide for how to set it accurately.
Using 1000+ DPI on wood
Very high DPI on wood causes overlapping scan lines to pile up heat, often resulting in a uniformly charred surface rather than distinct engraving. The wood's cellular structure simply can't hold detail at that scale. Stick to 254 DPI for wood in almost all cases.
Mismatching image DPI and scan interval DPI
In LightBurn's image mode, if you set a 600 DPI line interval but import a 72 DPI image, LightBurn upsamples the image — creating blur. Always match your image source DPI to your engraving interval DPI, or use LightBurn's dithering modes which handle this automatically.
Recommended starting approach
- Start at 254 DPI (0.1 mm interval) for any new material.
- If the fill looks too light or has visible scan lines at viewing distance, try 300 DPI (0.085 mm).
- If you're doing large fills or text above 8 mm tall, try 127 DPI first — you may not need the detail and you'll save significant time.
- For hard smooth materials (slate, anodized aluminum, polished dark acrylic), try 508 DPI (0.05 mm) on fine portrait detail.
- For photos on wood: use 254 DPI + Floyd-Steinberg or Jarvis dithering. Check focus before blaming DPI.
The material test grid generator lets you generate a range of power/speed combinations for any material — run one of those first, then dial in DPI as a second pass once power and speed are sorted.
Finding and confirming your laser's focus directly affects the maximum useful DPI — a laser 1 mm out of focus won't benefit from more than 127 DPI no matter what.
- Focus height gauges and spacers — a cheap way to confirm your focal distance every session
- OD7+ laser safety glasses (450 nm) — required whenever the beam is on, regardless of DPI setting
- Honeycomb bed — reduces reflection and holds material flat for consistent focus across the work surface
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Frequently asked questions
What DPI should I use for laser engraving wood?
254 DPI (a 0.1 mm line interval in LightBurn) is the standard starting point for wood engraving on diode lasers. It matches the practical detail limit of most diode laser spot sizes and the cellular structure of wood. For fast fills and large text, 127 DPI (0.2 mm interval) is faster and looks fine. Going above 508 DPI on wood gives no visible improvement and doubles your engraving time.
What DPI should I use for photo engraving on a diode laser?
Use 254 DPI with a good dithering algorithm — Floyd-Steinberg or Jarvis in LightBurn. Increasing DPI beyond 254 for photos on wood rarely improves results because the dithering pattern needs space between dots to create contrast. The dithering mode matters far more than raw DPI for photo quality. On hard materials like slate or anodized aluminum, 508 DPI can help fine portrait detail.
What is the difference between DPI and LPI in laser engraving?
DPI (dots per inch) and LPI (lines per inch) are used interchangeably in laser engraving, but technically measure different things. DPI counts how many laser pulses fire along a horizontal scan line. LPI counts how many horizontal scan lines fill one vertical inch. In practice, most laser software (including LightBurn) controls line density via a line interval setting in millimetres: 0.1 mm = 254 DPI/LPI, 0.2 mm = 127 DPI/LPI.
What is the maximum useful DPI for a 10W diode laser?
Most 10W diode laser modules produce a focused spot of roughly 0.05–0.08 mm. This puts the theoretical DPI ceiling at about 300–500 DPI. In LightBurn, this corresponds to a line interval of about 0.05–0.08 mm. Going below 0.05 mm line interval (above 508 DPI) means scan lines overlap and your engraving takes longer with no added detail. On soft materials like wood, the practical ceiling is lower — around 254–300 DPI — because wood's cellular structure absorbs the detail.
Does higher DPI make laser engraving look better?
Up to a point, yes. Increasing from 127 to 254 DPI is clearly visible — fine lines and gradients look smoother. Going from 254 to 508 DPI can help on hard smooth materials like slate, anodized aluminum, or dark acrylic. But on wood, the difference above 254 DPI is rarely visible because the laser's interaction with wood grain dominates the result. Higher DPI always means longer engraving time — doubling DPI roughly doubles the time.
Settings on this page are starting points based on aggregated community and manufacturer data, normalized and verified by lasertinkerer.com. Results vary with machine, material batch, focus accuracy, and ambient conditions. Always run a test on scrap material first. Operate at your own risk; follow your machine's safety manual.
Last verified: 2026-07-01.