Every LightBurn image setting explained

Image layers vs cut and line layers

Before any setting matters, you need the right kind of layer. LightBurn treats a photo and a shape as fundamentally different jobs.

• Image layer. When you drop a PNG or JPG onto the workspace, LightBurn puts it on an image layer. The laser scans back and forth like an inkjet head, turning the beam on and off (or scaling its power) pixel by pixel. This is the mode for every photo, portrait, texture and grayscale gradient.
• Cut / line layer. Vectors - lines, curves and closed shapes from an SVG - live on line layers. The laser follows the path once at a set power and speed to cut through or score a crisp outline. There is no dithering, no DPI, no scan angle.

The practical rule: tone comes from an image layer, edges come from a line layer. An SVG traced with the Image to SVG tool goes on a line layer; a dithered photo goes on an image layer. Many projects mix the two - a portrait inside a cut border.

The Image Mode dropdown, option by option

Select an image and open the Cut Settings (double-click the layer). The Image Mode dropdown is the single most important control here - everything below it only matters once you have picked the mode that suits your machine and material.

Threshold

Every pixel is forced to pure black or pure white at a cut-off you set. No dots, no shading - just a hard 1-bit image. It is useless for photos but perfect for logos, stencils, signatures and clean line art where you want solid fills, not tone.

Ordered

A fast, patterned dither that lays dots on a fixed grid. It engraves quickly and predictably, but the regular crosshatch pattern is visible up close and looks mechanical. Reach for it when speed matters more than photographic quality, or for a deliberately retro, patterned look.

Atkinson

An error-diffusion dither (the one Apple used on the original Macintosh) that spreads only part of the error to neighbours. The result is high contrast and clean, with open highlights and fewer dots than Jarvis or Stucki. Atkinson flatters faces on wood and slate and resists the "mud" problem on lasers whose dots tend to merge.

Jarvis

A wider error-diffusion kernel that produces smooth, photographic mid-tones with an open, evenly spread dot pattern. Jarvis is the workhorse for photo engraving on diode lasers - it holds gradients well and is forgiving when your dots bloom slightly. If you only learn one dither, learn this one.

Stucki

Close cousin to Jarvis with an even larger diffusion kernel, giving very smooth tonal transitions and sharp detail. It shines on higher-resolution and CO2 machines that can resolve the finer dot placement. On a coarse diode it can look almost identical to Jarvis, so test both.

Newsprint (halftone)

A classic halftone: tone is rendered as dots that grow and shrink on a regular grid, exactly like a printed newspaper photo. You control the angle and the cell size. It is a stylistic choice, not a fidelity one - great for a vintage, screen-printed aesthetic, and useful on materials too coarse to hold fine error-diffusion dots.

Grayscale

No dithering at all. LightBurn varies laser power per pixel so darker pixels burn deeper or blacker. In theory the most faithful mode; in practice it demands a linear, well-calibrated power response and a material with a wide tonal range. On a tuned CO2 marking anodized aluminum or dark acrylic it is stunning; on a typical diode it tends to band and wash out.

Pass-Through

The mode that trips up the most people, and the one that matters most if you prepared your image elsewhere. It tells LightBurn not to process the image at all - see the next section.

Pass-Through: the one that saves your dither

Here is the trap. If you dither a photo in EngraveBot's Dithering Lab, you get a pure black-and-white PNG - the dots are already placed exactly where you want them. Drop that into LightBurn on, say, Jarvis mode, and LightBurn dithers it again. You are dithering an image that is already dithered, which scrambles the careful dot pattern into a darker, muddier mess.

Pass-Through prevents that. Tick it (or choose the Pass-Through image mode, depending on your LightBurn version) and LightBurn burns each pixel literally: black pixel = beam on, white pixel = beam off. No re-dithering, no re-sampling of tone. Your EngraveBot dots reach the material exactly as designed.

One catch: because LightBurn is not resampling, the image's own pixel resolution now sets the effective DPI. Export the PNG already sized for the DPI you want (EngraveBot lets you set this), and set the line interval to match so one pixel maps to one scan line.

DPI, lines per inch and line interval

DPI (dots per inch), lines per inch and line interval are three names for the same idea: how tightly the scan lines are packed. Line interval is just the metric inverse of DPI - interval mm = 25.4 ÷ DPI. LightBurn shows interval in mm; most people think in DPI. Both control the same thing, and higher is emphatically not better.

Pack the lines closer than your laser can resolve and the dots overlap, flood the surface and erase the detail you were trying to keep. The right number matches the smallest clean dot your machine actually makes.

In LightBurn the interval field lives right in the image Cut Settings. Set it, and the DPI readout updates to match. Our Laser Calculator converts freely between DPI, interval, physical size and estimated engraving time so you are not doing the arithmetic by hand.

Scan angle: why 0 vs 90 matters

Scan angle sets the direction the laser sweeps across the image. The default is 0 degrees - the head runs left-to-right, stepping down line by line. Rotate it to 90 degrees and it scans top-to-bottom instead. This seemingly cosmetic choice changes the result for two real reasons:

• Material grain. Wood has a direction. Fine detail scanned across the grain often reads cleaner than detail scanned along it, because the grain no longer lines up with your scan lines and competes with them. If a 0-degree burn looks streaky on wood, try 90.
• Mechanical banding. Every machine has tiny inconsistencies in one axis - belt tension, stepper resolution. If you see faint horizontal bands, rotating the scan angle moves them to the other axis, where they may be far less visible.

Angles like 45 degrees are a middle path: they hide both grain and axis-specific banding by aligning with neither, at the cost of a slightly slower scan. For a portrait fighting visible wood grain, 45 degrees can be the fix nothing else provides.

Overscan and bi-directional scanning

Two settings work together to control the physical sweep.

Bi-directional scanning

With bi-directional (sweep) scanning on, the laser fires on both the left-to-right and right-to-left passes, roughly halving engrave time. With it off, the head fires one way and returns blank - slower, but it sidesteps an alignment error. If your two directions don't line up you get a faint doubled or "ghosted" look on vertical edges; fix it with a scanning offset adjustment (LightBurn has a table) or, quickly, by turning bi-directional off.

Overscan

The head needs room to decelerate, turn and accelerate back to speed at the end of each line. Overscan adds a small margin outside the image where the head travels but does not fire, so the beam engraves only at constant speed. Without it, the left and right edges burn darker because the head is moving slowly there and dumping more energy per millimetre. A value of 2.5% is a sensible default; raise it at high speeds. Overscan only applies when bi-directional scanning is on.

Negative image and dot width correction

Negative image

Ticking Negative Image inverts the file - blacks become whites and vice versa - inside LightBurn, without editing your source. This is essential on light-marking materials, where the laser removes a dark surface to reveal a pale mark: slate, painted tiles, anodized aluminum, coated metal, some glass. On these you burn the highlights, not the shadows, so the photo must be inverted. On dark-marking materials like wood or leather you leave it off.

Dot width correction / dithering density

When a laser fires, the burnt dot is usually a little larger than the theoretical pixel. Dot width correction shrinks each fired line slightly to compensate, so dense dark areas don't bleed into solid black and swallow detail. Start at 0; if your darkest regions block up into featureless black, add a small correction (often 0.05–0.15 mm) to open them back up. A related dithering density control does the same job from the other direction. The goal for both: keep the darkest tones just short of flooded black.

Power, speed and image darkness

Two numbers set how hard the laser hits, and they interact differently depending on your image mode.

• Max Power is the ceiling. In dither modes every fired dot burns at Max Power - the image tone comes from how many dots, not how hard each one hits. In grayscale mode, Max Power is what a pure-black pixel gets.
• Min Power matters in grayscale mode: it sets what the lightest engraved pixel receives, and LightBurn scales between Min and Max across the tonal range. Get the Min/Max window right and grayscale tones map smoothly; get it wrong and highlights vanish or shadows block up. In pure dither modes Min Power has little effect because dots are simply on or off.
• Speed trades darkness for time. Slower means more energy per millimetre and darker, deeper marks; faster is lighter and quicker. On most diodes you dial speed to control overall darkness while leaving Max Power near the top of the material's safe range.

These numbers are always starting points. Your exact figures depend on your laser's real optical output, lens, material batch and focus - none of which a guide can know. The only honest way to lock them in is to burn a test grid: a small array of squares, each at a different power/speed pair. Burn it once on an offcut, pick the best square, use those numbers. Generate one with the free Test Grid Generator.

Recommended image mode by material and machine

A starting map from surface and machine to image mode. Treat the modes as confident defaults and the power/speed as first guesses to refine with a test grid.

For the per-material deep dives - power ranges, focus and finish - see the guides for wood, metal, acrylic, leather and slate, and the community Settings DB.

How EngraveBot lines up with LightBurn

EngraveBot exists to do the hard part - tone, contrast, dithering and resolution - before the file ever reaches LightBurn, so you spend LightBurn time placing the piece rather than fighting the image engine.

• Same algorithms. The Dithering Lab offers the same error-diffusion families LightBurn does - Jarvis, Stucki, Atkinson, Ordered - so you can preview the exact dot pattern on simulated material and pick the winner before you burn anything.
• Export sized for your DPI. The Photo to Laser tool lets you set the output resolution, so the PNG's pixels already match the line interval you plan to use. Import on Pass-Through and one pixel maps to one scan line.
• Ready-to-run .lbrn2. EngraveBot can emit a complete LightBurn project with the image already on an image layer, Pass-Through set, and your chosen power, speed and interval filled in. You open it, position it, and burn - no dropdown archaeology required.

The workflow end to end: prepare and dither in EngraveBot → export a PNG or a .lbrn2 → confirm Pass-Through, interval and scan angle in LightBurn → burn a test grid → run the real piece. For the upstream half, start with converting a photo into a laser-ready file and the best dithering settings guide.

Prep and export your photo - free, in your browser

Frequently asked questions

When should I use Pass-Through in LightBurn?

Use it whenever the image is already a pure black-and-white dithered file, such as one exported from EngraveBot. Pass-Through burns the pixels exactly as drawn and skips LightBurn's own dithering, so you don't dither an already-dithered image and turn it muddy.

What is the difference between dither and grayscale?

Dither modes (Atkinson, Jarvis, Stucki, Ordered, Newsprint) make pure black-or-white dots - reliable on diode lasers and textured materials. Grayscale varies laser power per pixel and only looks good on machines with linear, well-tuned power scaling, like a calibrated CO2.

Which image mode is best for photos?

Jarvis or Stucki for the most photographic result on most machines; Atkinson for cleaner, higher-contrast portraits with fewer dots; Grayscale on well-calibrated CO2 setups. Threshold and Newsprint are for line art and halftone styles, not smooth faces.

What scan angle should I use?

0 degrees is the default and works for most jobs. Switch to 90 degrees when horizontal banding shows or wood grain runs horizontally; 45 degrees hides both grain and banding at a small speed cost.

Keep going

Go upstream to converting a photo into a laser-ready file and the best dithering settings for laser engraving, or pick your surface: wood, slate or metal. When you are ready, prep the file in the Photo to Laser tool.