Quick answer: good first settings
If you need a practical starting point before reading the full guide, use the table below. It is not a final recipe, but it gives you a controlled first export for a real material test.
| Job | Start with | Export | First check |
|---|---|---|---|
| Wood portrait | Normal Photo, 254 DPI, Floyd-Steinberg, moderate contrast, gentle gamma lift. | PNG | Eyes readable, shadows not burned into one dark patch. |
| Slate portrait | Negative, 254 or 300 DPI, Floyd-Steinberg or Jarvis, stronger midtone contrast. | PNG | Face not washed out after inversion; highlights still separated. |
| Black anodized aluminum | Negative, 508 DPI or tested Custom DPI, Floyd-Steinberg or Jarvis. | PNG or 1-bit BMP | Fine facial dots survive the marking settings. |
| Glass photo | Usually Negative, 254 or 300 DPI, lower contrast, Floyd-Steinberg or Ordered/Bayer. | PNG | No harsh white crust, chipping or lost skin softness. |
| Leather photo | Normal Photo, 254 DPI, Atkinson or Floyd-Steinberg, lighter shadows. | PNG or 1-bit BMP | Heat spread does not turn details smoky or dirty. |
What changed in the current editor
The current PhotoEngraving.online editor is more than a simple photo filter. These features are now part of the normal workflow and are reflected throughout this guide.
The Crop Photo tool lets you remove empty background and choose Free, Original or Square framing before dithering, material preview and export.
Use Original + Output for editing decisions, Output for final black-and-white inspection and Material Preview for rough visual context.
Wood, slate, dark surfaces, stainless steel, glass, leather and ceramic tile previews help with inversion and contrast choices.
Floyd-Steinberg, Atkinson, Jarvis and Ordered/Bayer are available directly in the editor, so the exported file already contains the dot pattern.
Set output width in millimeters, choose 254, 300, 508 or Custom DPI and check the calculated pixel size before export.
Both export paths are intended for laser software and include DPI metadata. PNG is the default; BMP helps strict black-and-white workflows.
Step-by-step editor workflow
Photo engraving becomes easier when the image preparation and the laser test are treated as one workflow. The purpose of PhotoEngraving.online is to make the image side predictable: you prepare a black-and-white raster image with the correct physical size, DPI and dot pattern before you import it into LightBurn, LaserGRBL, XCS, EZCAD or another laser program.
The editor does not replace material testing. It gives you a controlled starting file, so your test is about laser power, speed, focus and material behavior instead of accidental scaling, repeated compression or double dithering.
Brightness, contrast and gamma
Brightness moves the whole image lighter or darker. Contrast separates light and dark areas. Gamma is especially useful because it changes midtones without moving pure black and white points as aggressively. For portraits, gamma often helps open the face while keeping hair and eyes strong.
Sharpness
Sharpening can make eyes, hair and edges more readable, but too much sharpening creates halos and harsh dots. Use the magnifier after sharpening. If the output looks crispy on screen, it may engrave as noise on wood or rough stone.
How laser photo engraving really works
A photo on a screen is made of light. A laser engraving is made of physical marks on a surface. Those marks may be burned wood, bleached anodized coating, frosted glass, ablated paint, melted acrylic or exposed metal coating. That is why the same image can look excellent on one material and muddy on another.
PhotoEngraving.online focuses on the part you can control before the laser job starts: tones, dot pattern, output size and pixel density. The laser and material still decide how those pixels become real marks.
Some materials behave almost like an on/off switch: either they mark or they do not. Dithered black-and-white output is useful here because tone is created by dot density, not perfect power modulation.
A laser dot is rarely the same size as one image pixel. Heat, smoke, grain and coating thickness can make dots spread. If dots grow, a lower DPI or lighter image can look cleaner than a very fine file.
A small keychain must read from close distance. A large plaque can use coarser dots because the viewer stands farther away. Use the tool's millimeter size and pixel preview to judge detail at the real final size.
What the editor can and cannot do
The editor can make a photo more suitable for engraving, but it cannot invent detail that is not in the source. It can brighten a face, increase midtone separation, sharpen after resizing, create a controlled black-and-white dither pattern and export a file with DPI metadata. It cannot know your real laser spot size, your lens condition, air assist behavior, bed flatness, focus offset or the exact material coating.
Laser types and what they change
The PhotoEngraving.online output is a raster image. The same PNG or BMP can be imported into many laser programs, but the laser source determines what materials make sense and whether the mark gets darker, lighter, frosted or removed.
| Laser type | Where it usually works well | What to watch in the editor | Practical photo note |
|---|---|---|---|
| Diode laser | Wood, plywood, leather, painted surfaces, some coated metals and some dark acrylics. | Use clear contrast and avoid extremely high DPI on soft materials. Dot growth can make shadows close quickly. | 254 or 300 DPI is often a practical starting range for wood-style photo work. |
| CO₂ laser | Wood, acrylic, glass, leather, paper, rubber and many coated materials. | Glass and acrylic often need inversion and careful contrast. Wood still needs conservative shadow handling. | Use test crops because glass can look good in preview but rough or flat after engraving. |
| Fiber laser | Anodized aluminum, coated metal, stainless marking, plastics and some industrial materials. | Fine dots can work well, but material response varies strongly. Use the tool to control image size and DPI, then tune marking parameters in your fiber software. If your machine supports pulse width control, a MOPA fiber may behave differently from a standard Q-switched fiber. | High detail may be possible, but test power, speed, frequency, pulse width if available, lens/spot size and bitmap settings. |
| UV laser | Glass, plastics, coated materials and heat-sensitive surfaces. | Use clean tones and avoid over-sharpened patterns unless the material really holds them. | UV can preserve detail, but the final contrast depends heavily on the surface reaction. |
Choosing a photo that will engrave well
The input photo sets the ceiling for the final engraving. PhotoEngraving.online can convert a normal photo into a laser-ready raster, but it works best when the original has real detail, clear subject separation and usable midtones.
Sharp face, clear eyes, simple lighting, visible hair texture, enough pixel resolution, a subject that stands away from the background and no heavy social-media filter.
Tiny web photos, motion blur, faces in deep shadow, white skin highlights with no texture, very busy backgrounds, strong compression artifacts and photos where the important subject is too small.
A quick photo check before upload
- Open the photo at 100% zoom. If the eyes are already blurry, the engraving will not magically become sharp.
- Ask whether the subject is readable in black and white. Color contrast alone is not enough.
- Check if the background competes with the face. A busy background may become noisy after dithering.
- Use a larger source image than the final output whenever possible. Scaling down is safer than enlarging a tiny file.
Crop, preview modes and material preview
The current editor has three separate preview ideas: the clean laser output, the side-by-side original/output comparison and an approximate material simulation. Use them for different decisions.
Crop removes distracting background before resizing, dithering, material preview and export. Use Free for normal framing, Original when you want to keep the source aspect ratio and Square for plaques, tiles, coasters or social-photo style compositions.
Use this view while adjusting tones. It helps you see whether lost detail was already missing in the source photo or was caused by contrast, gamma, sharpness, DPI or dithering choices.
Use the single output view before export. It shows the black-and-white laser-ready raster that will be written into the PNG or BMP file.
How to use Material Preview
Material Preview simulates how the same black-and-white dot pattern might look on wood, slate, dark surfaces, stainless steel, glass, leather or ceramic tile. It adds approximate base color, mark color, texture and dot gain, so it can make inversion and contrast decisions easier.
| Preview material | What it helps you judge | Common starting thought |
|---|---|---|
| Wood | Dark burned marks on a light surface, plus possible dot growth. | Normal Photo is usually the first test. Keep shadows open. |
| Slate | Light engraved marks on a dark surface. | Negative is often the right first test. |
| Dark surfaces | Light or silvery marks on black anodized or dark coated material. | Try Negative and check whether faces still read naturally. |
| Stainless steel | Approximate contrast on a reflective metal-like base. | Use only as a rough visual guide; marking spray, fiber settings and coating behavior matter a lot. |
| Glass | Frosted light marks and a softer visual response. | Test crop carefully because glass can chip, haze or look flatter than the preview. |
| Leather | Dark marks with strong dot growth and organic texture. | Lower detail and conservative contrast are often cleaner. |
| Ceramic tile | Dark marks on a pale surface with coating/glaze uncertainty. | Treat every tile and coating as a separate recipe. |
DPI, line interval and physical size
In the editor, the most important size field is the real engraving width in millimeters. DPI then decides how many image pixels will fit into that physical width. The tool shows the calculated pixel size so you can avoid files that are too small to hold detail or too large for a practical raster job.
width in pixels = (width in mm ÷ 25.4) × DPI
line interval in mm = 25.4 ÷ DPI
DPI = 25.4 ÷ line interval in mm
| DPI in the editor | Approx. line interval | Good starting use | Watch out for |
|---|---|---|---|
| 254 DPI | 0.100 mm | Soft wood, plywood, MDF, slate, stone, glass and faster test pieces. | Small portraits may lose fine facial detail if the physical size is also small. |
| 300 DPI | 0.085 mm | General photo work on wood, plywood, glass, slate, HDF and plastic when the material can keep decent dot separation. | Still test dot growth; some woods close shadows quickly. |
| 508 DPI | 0.050 mm | Acrylic, laminates, coated metals, anodized aluminum, ceramics and surfaces that can hold fine dots. | More pixels do not help if the laser spot and material cannot reproduce them. Jobs also become slower and heavier. |
| Custom DPI | Your value | Use when you already know the preferred line interval for your lens, laser and material, or when tests show that a value between presets works better. | The editor accepts values from 1 to 2400 DPI, but stay realistic. A very high DPI can create heat buildup and soft shadows instead of more detail. |
Pixel size matters too
A photo does not become better just because it has high DPI metadata. What matters is the combination of physical size, pixel count, laser spot and material response. If you engrave an 80 mm wide portrait at 254 DPI, the output is roughly 800 pixels wide. At 508 DPI, it is roughly 1600 pixels wide. The second file has more detail only if your laser and material can actually mark it cleanly.
Test and calibration workflow
Calibration is not a separate topic from image preparation. It is the step that tells you whether the PhotoEngraving.online file is suitable for your exact material and laser settings.
Make a useful test crop
Do not test only a blank square or a random corner. For portraits, choose a crop that includes an eye, hair, skin, a dark shadow and a bright highlight. A useful crop is often 25–40 mm wide. It saves material and gives enough information to predict the full engraving.
Too little power gives a weak image. Too much power closes shadows, burns wood, melts plastic or makes glass rough. Test power in small steps.
Slower speed usually adds energy. Faster speed can keep detail cleaner, but the mark may become pale. Keep speed and power notes together.
Tighter spacing gives more lines, but also more heat and overlap. If the image is muddy, a lower DPI can be better than more detail on paper.
Test in a controlled grid
Export one file from the editor and engrave it in a small grid with different laser powers and speeds. If the best result is still too dark or too light, go back to the editor and adjust gamma, contrast, photo type or dithering. This separation keeps the process understandable.
Dithering algorithms in plain language
Dithering turns gray tones into patterns of black and white pixels. From normal viewing distance, the eye blends those pixels into lighter and darker areas. This is why PhotoEngraving.online can export a simple laser-ready black-and-white file instead of relying on every laser program to interpret grayscale in the same way.
| Dithering method | How it tends to look | Good use in the editor | What to watch |
|---|---|---|---|
| Floyd-Steinberg | Balanced, familiar photographic texture with good detail. | Start here for most portraits and general photo tests. | Can look noisy if the source photo already has heavy grain or compression. |
| Atkinson | Softer, lighter, sometimes more vintage-looking. | Try when the output is too dark, when wood burns heavily or when you want a gentler portrait. | Can lose deep shadows and some fine contrast. |
| Jarvis | Smoother tonal transitions and more distributed dots. | Try for skin tones and materials that can hold fine detail. | Can become too dense on materials with dot growth. |
| Ordered / Bayer | Regular visible pattern instead of organic error diffusion. | Useful for logos, graphic-style images, large smooth tone areas and workflows where a predictable texture is preferred. | On portraits and small faces, the pattern may look artificial. Compare it against Floyd-Steinberg or Jarvis on the same crop. |
Should you dither in the editor or in laser software?
Use one dithering stage only. If you use PhotoEngraving.online to create a dithered black-and-white PNG or 1-bit BMP, your laser software should preserve that file as closely as possible. If you prefer to dither inside LightBurn, LaserGRBL or another program, export a suitable grayscale image from a different workflow and do not pre-dither it first.
Material-specific advice
The same image file will not behave the same on every material. In the editor, this mainly affects Photo Type, brightness, gamma, contrast, DPI and dithering choice. On the laser, it affects power, speed, focus, air assist and finishing.
| Material | How the image usually forms | PhotoEngraving.online preparation tip | Common problem |
|---|---|---|---|
| Light wood | Laser burn becomes darker than the surface. | Use Normal Photo, open shadows with gamma, avoid excessive contrast and start around 254–300 DPI. | Face becomes too dark, wood grain dominates or smoke stains light areas. |
| Bamboo and plywood | Similar to wood, but glue layers and grain can react unevenly. | Use slightly softer contrast and test Atkinson or Floyd-Steinberg. | Banding, uneven darkness and loss of skin detail. |
| Slate and stone | Engraved areas often become lighter. | Use Negative Photo Type early. Increase midtone contrast and check whether highlights stay readable. | Image looks flat because the inversion or contrast is wrong. |
| Glass | Laser creates a frosted or rough mark that appears light. | Use Negative for many workflows, avoid extremely dense shadows and test lower contrast than you expect. For CO₂ glass tests, a moist paper towel or application tape can sometimes make the mark cleaner and reduce rough chipping. | Chipping, harsh white spots, rough texture and lost facial softness. |
| Clear acrylic | Engraved areas frost or scatter light. | Prepare a clean high-contrast file, often with inversion depending on the viewing/background setup. | Photo only becomes readable with a dark backing or side lighting. |
| Dark acrylic | Mark may become lighter or may remove surface/color. | Test Negative and 300–508 DPI depending on how fine the surface holds dots. | Too much heat melts details and makes skin look plastic. |
| Black anodized aluminum | Laser removes or changes the dark coating, often creating a light mark. | Use Negative, consider finer DPI and compare Floyd-Steinberg with Jarvis on a test crop. | Fine dots may vanish if the marking parameters are not tuned. |
| Painted/coated metal | Laser removes paint or coating to reveal another color below. | Use the editor to make a clean black-and-white file and test how much detail the coating can preserve. | Overburn removes too much coating and destroys tonal separation. |
| Leather | Laser darkens, burns or discolors the surface. | Use lower energy tests, moderate DPI and avoid dense black regions in the editor. | Heat marks spread and the image becomes dirty or smoky. |
Recommended workflow by material
Use the table below as a practical first pass, not as a fixed recipe. Prepare the file in PhotoEngraving.online, engrave a small crop, then change only one variable at a time.
| Material | Photo Type | DPI start | Dithering start | Practical note |
|---|---|---|---|---|
| Light wood | Normal Photo | 254–300 DPI | Floyd-Steinberg or Atkinson | Keep shadows open. Too much contrast or power quickly turns skin and hair into a dark mass. |
| Slate / stone | Negative | 254–300 DPI | Floyd-Steinberg or Jarvis | The mark is usually lighter than the surface, so check inversion and midtone contrast before the full job. |
| Glass | Usually Negative | 254–300 DPI | Ordered/Bayer or Floyd-Steinberg | Avoid heavy solid dark areas. Test a moist paper towel or application tape on CO₂ glass workflows. |
| Clear acrylic | Depends on background | 300–508 DPI | Floyd-Steinberg or Jarvis | Photos often become more readable with a dark backing, edge light or intentional viewing background. |
| Black anodized aluminum | Negative | 508 DPI or Custom DPI | Floyd-Steinberg or Jarvis | Fine dots can disappear if power, speed or frequency are not tuned. Test small facial details. |
| Leather | Normal Photo | 254–300 DPI | Atkinson or Floyd-Steinberg | Use lower energy tests and avoid dense black areas; heat spread can make the image dirty. |
Extra glass note
Glass is easy to overdrive because the engraved mark is light, not dark. If the result looks harsh, reduce density before increasing power. On CO₂ lasers, many workshops test a moist paper towel, dish soap film or application tape to control surface chipping. Always test on the same type of glass, because coated, tempered and cheap picture-frame glass can react differently.
Mini workflows by material
Use these as short, repeatable recipes for the first test crop. After the first engraving, change only one thing: image settings, DPI, dithering or laser parameters.
Crop close enough that the face fills the engraving. Start with Normal Photo, 254 DPI, Floyd-Steinberg, brightness near default, moderate contrast and gentle gamma lift. Export PNG, import at the same millimeter width and test a crop with an eye, hair and shadow.
Start with Negative because slate usually engraves lighter. Try 254 or 300 DPI, Floyd-Steinberg or Jarvis and stronger midtone contrast. Use Material Preview for a rough inversion check, then trust the real slate test.
Start with Negative, 508 DPI or a tested Custom DPI, Floyd-Steinberg or Jarvis and a clean high-resolution source. Export PNG or 1-bit BMP and tune marking settings so tiny dots appear without merging or disappearing.
Start with Negative for many glass jobs, 254 or 300 DPI and lower contrast than you would use on wood. Compare Floyd-Steinberg and Ordered/Bayer. Test a small crop because glass roughness and chipping are not visible in the browser preview.
Start with Normal Photo, 254 DPI, Atkinson or Floyd-Steinberg and lighter shadows. Leather spreads heat, so avoid dense black areas. Keep sharpness conservative and test lower energy before trying a darker file.
Start with Normal Photo for dark marks on pale tile, or Negative if your coating produces a light mark. Try 300 or 508 DPI only if the glaze or coating holds dots cleanly. Treat each tile, spray and coating as a separate recipe.
Starting settings and test ideas
There is no universal laser setting table that works for every machine. A 10 W diode, 60 W CO₂ and 30 W fiber laser do not share the same power scale. The safest use of PhotoEngraving.online is to make a consistent image file, then find the laser settings on your own material.
Start with Normal Photo, 254 or 300 DPI, Floyd-Steinberg or Atkinson, controlled gamma and moderate sharpness. Test a grid where power increases slowly. If shadows close, reduce power, lower DPI or make the image lighter.
Start with Negative. Try 254 or 300 DPI on slate and dark acrylic, and 508 DPI or Custom DPI on black anodized aluminum if your laser can hold fine dots. Compare Floyd-Steinberg and Jarvis. Make sure the face is not washed out before running a full portrait.
Use small tests and watch heat. Try 300 or 508 DPI, or a tested Custom DPI, only if dots stay separate. Compare Floyd-Steinberg, Jarvis and Ordered/Bayer on glass or large smooth tone areas, then tune speed and power in your laser software.
A useful first test matrix
Use one exported file and engrave a small grid at three powers and three speeds. Pick the best laser setting first. Then, if the image still needs improvement, return to the editor and compare one image variable: Photo Type, gamma, contrast, DPI or dithering.
Software workflow after export
Laser software is powerful, but it can also change your image after export. The whole point of preparing a final file in PhotoEngraving.online is to keep the raster predictable. After import, confirm physical size, avoid extra image processing and set laser parameters deliberately.
Import the PNG or BMP, check physical size, line interval and image mode. If the file is already dithered, use pass-through or the closest workflow that prevents reprocessing. Confirm overscan for raster jobs.
Pay attention to dithering and line-to-line options. If the editor already created the final black-and-white pattern, avoid applying another dithering conversion during import.
Check bitmap mode, size, engraving quality and whether the app changes contrast or dithering. Confirm that the imported dimensions match the millimeter size from the editor.
Import the raster at the intended physical size and confirm resolution/scaling. Fiber bitmap marking also depends on frequency, pulse width when available, lens/spot size, hatch or bitmap settings and material coating. A MOPA fiber may need a different recipe than a standard Q-switched fiber.
Check that the sender does not resize or resample the file unexpectedly. A good image can fail if the G-code is generated at the wrong physical size.
Avoid changing brightness, contrast, inversion or dithering again after export unless you intentionally start a new test version.
Pass-through and pre-dithered files
When a file already contains a final black-and-white dot pattern, it should not be interpreted as a normal grayscale photograph again. Use pass-through where your software supports it, or choose settings that preserve black pixels as mark pixels and white pixels as no-mark pixels.
Common import checks
| Software | Check first | Avoid |
|---|---|---|
| LightBurn | Confirm imported size in millimeters, use pass-through or a true black-and-white workflow for pre-dithered files, and check line interval/overscan. | Applying another image mode or dithering algorithm to an already dithered export. |
| LaserGRBL | Confirm image size and line-to-line settings. Preserve the black-and-white pattern if the file came from PhotoEngraving.online. | Re-running import dithering unless you intentionally start from a grayscale workflow. |
| xTool XCS | Check bitmap mode, physical dimensions, quality setting and whether the app changes contrast or dithering. | Letting the software resize the image without noticing. |
| EZCAD / fiber workflows | Confirm bitmap scale, lens/field size and marking parameters. Tune speed, power, frequency and pulse width if available on your machine. | Assuming a screen preview predicts coating reaction on metal. |
Overscan and borders
Raster engraving often needs overscan so the head reaches stable speed before marking. If edges are darker or lighter, check acceleration, overscan and scan direction in the laser software rather than changing the photo first.
Export and file handling
For photo engraving, keep the final file simple and predictable. PhotoEngraving.online exports raster files intended for laser software. The exported file is the clean black-and-white output, not the colored material preview. Use the format that best fits your workflow, then keep the original photo and the exported test files organized.
| Format | Use it when | Avoid it when | Guide note |
|---|---|---|---|
| PNG | You want a clean raster file for LightBurn, XCS, LaserGRBL, EZCAD and most general workflows. | Your specific software has poor PNG import or ignores metadata. | Recommended default. The exported PNG includes DPI metadata to help preserve physical size. |
| 1-bit BMP | You want a strict black-and-white bitmap workflow or your laser software handles BMP more predictably. | You need a smaller compressed file or your software handles PNG better. | The BMP is written as a 1-bit file with black/white palette and DPI metadata. |
| JPG | As an input source if the original is high quality. | As a final repeated export format. | JPEG compression can create artifacts that become visible after dithering. |
| SVG | Vector logos, outlines and shapes. | Final dithered photo pixels. | A dithered photo is raster data. PNG or BMP is usually the correct final format. |
Check scaling on import
Even when a file includes DPI metadata, always confirm the physical size after import. If you prepared an 80 mm wide image in the editor, the laser software should also show 80 mm. If it does not, resize the imported image to the intended dimension before engraving.
Large output behavior
The editor protects the browser from accidentally rendering huge files. If the selected output is very large, live preview can pause and the editor may ask for confirmation before export. If you hit that warning, reduce physical width, lower DPI or crop tighter unless you truly need a very large raster job.
Download names
Exports use practical names such as laser-80-0mm-254dpi.png or laser-80-0mm-254dpi.bmp. Add your own material and test information after downloading if you keep multiple versions.
Keep your source file
Save the original photo and label exported versions with material and settings, for example: portrait_slate_negative_300dpi_floyd.png. This makes later tests easier to compare.
Troubleshooting common photo engraving problems
| Problem | Likely cause | What to try in PhotoEngraving.online | What to check on the laser |
|---|---|---|---|
| Face is too dark and muddy | Too much energy, crushed shadows, too dense dithering or material dot growth. | Raise gamma, lower contrast, try Atkinson, reduce sharpness or test lower DPI. | Lower power, increase speed, check focus and smoke extraction. |
| Image is too pale | Too little energy or an overly light file. | Increase contrast, lower gamma slightly, use Normal instead of an overly light preset or try Floyd-Steinberg. | Increase power, reduce speed or check whether the material can mark enough. |
| Output looks inverted | Wrong Photo Type for the material. | Switch between Normal Photo and Negative, then compare the preview. | Confirm whether the laser mark becomes darker or lighter than the surface. |
| Dots look too coarse | Low DPI, small physical size or large viewing distance mismatch. | Increase DPI or physical size if the material can hold detail. | Check line interval, spot size and whether higher DPI just adds heat. |
| Dots blur together | DPI too high, too much energy, soft material or poor focus. | Use lower DPI, lighter gamma, Atkinson or less contrast. | Refocus, reduce power, increase speed, improve air assist or choose a harder material. |
| Background is noisy | Busy original background or compression artifacts. | Prepare a cleaner source before upload, reduce sharpness or crop/remove background in another editor first. | Use a test crop to see whether the background noise matters at final viewing distance. |
| Subject is too small in the final engraving | The photo has too much empty background or the crop was not applied before setting output size. | Use Crop Photo, then check the recalculated millimeter size and pixel size before export. | Confirm the imported file still matches the intended width. |
| Material preview looks different from the engraving | Material Preview is only an approximate visual simulation. | Use it for inversion and rough contrast decisions, not as a final prediction. | Test speed, power, focus, material coating, cleaning and finishing on a real offcut. |
| Live preview says it is paused | The selected output is very large. | Crop tighter, reduce width or lower DPI. Use full export only when the pixel count is intentional. | Expect large raster jobs to be slower in laser software too. |
| Software changes the image | Double dithering, resampling, contrast adjustment or wrong import mode. | Export a fresh PNG/BMP and use one dithering method only. | Use pass-through or a true black-and-white import workflow where available. |
| Physical size is wrong | DPI metadata ignored or image was resized after import. | Check the millimeter width and pixel size in the editor before export. | Manually set the imported image to the intended width in the laser software. |
Laser photo engraving glossary
These terms appear often in photo engraving guides and laser software. Knowing them makes it easier to compare editor settings with real machine settings.
Dots per inch. In the editor, DPI links pixel count to the real physical size in millimeters.
Distance between raster lines. It is the inverse of DPI: line interval in mm = 25.4 ÷ DPI.
A method that turns gray tones into black-and-white dot patterns so tone is created by dot density.
The real laser mark becomes larger than the image pixel because of heat, smoke, coating or material texture.
A midtone control. It can open or deepen faces without moving pure black and white as aggressively as contrast.
Black and white are swapped. It is useful when the laser mark becomes lighter than the material surface.
A strict black-and-white bitmap format. PhotoEngraving.online exports it with a black/white palette and DPI metadata.
A laser software mode or workflow that preserves a prepared bitmap instead of changing contrast or dithering again.
A browser-only simulation of surface color and mark color. It is not the downloaded laser file.
Safety: do not skip this part
Photo engraving often means long raster jobs, repeated tests and a lot of smoke or fumes. The editor prepares the image, but safe laser operation is still your responsibility. Follow the manual for your exact machine, enclosure, ventilation and material.
- Never engrave unknown plastic. PVC, vinyl, many artificial leathers, ABS, polycarbonate, PTFE/Teflon, PVB, halogenated plastics and flame-retardant materials can release dangerous fumes, corrosive gases or damaging residue.
- Be cautious with carbon fiber, fiberglass, epoxy, phenolic resins and unknown coated materials. They can produce hazardous dust, fumes or residues that are not suitable for a hobby enclosure.
- Use suitable ventilation and filtration for the exact material you engrave. Long photo raster jobs can create more smoke exposure than a short logo engraving.
- Do not leave a laser running unattended, especially on wood, paper, leather, cardboard or coated material.
- Use correct eye protection and a proper enclosure for your laser wavelength. Diode, CO₂, fiber and UV lasers need different protection.
- Keep a fire extinguisher nearby, keep the bed clean of debris and avoid stacked scraps that can catch fire during slow raster jobs.
- When testing new materials, start small, stay present and watch the reaction carefully before committing to a full-size photo.
Advanced techniques once the basics work
After you can make a reliable test crop, you can start improving the final look. The editor gives fast global controls; for difficult portraits, combine it with careful source editing before upload.
Make separate versions for different materials
A wood version may need open shadows and gentle sharpening. A slate version may need inversion and stronger midtone contrast. A dark anodized aluminum version may need finer detail and a different dot density.
Edit locally before upload
The PhotoEngraving.online sliders affect the whole photo. Real portraits sometimes need local work: brighten only the eyes, soften only the background, remove a dark object behind the head or reduce strong highlights on the skin. Do those local edits in a photo editor first, then use PhotoEngraving.online for the laser-ready conversion.
Use the magnifier for dot decisions
The normal preview helps with composition. The magnifier helps with engraving structure. Look at whether the dot pattern preserves the eyes, whether the hair becomes a noisy mass and whether the background creates distracting texture.
Compare dithering on the same crop
Do not compare Floyd-Steinberg on one photo and Jarvis on another. Use the same physical size, DPI, crop and laser settings. Only then will the difference between dithering methods mean something.
Try intentional defocus carefully
A small defocus can soften harsh dots on some materials, especially glass or acrylic. It can also destroy fine detail, so test it and write down the offset.
Watch scan direction
Wood grain, brushed metal and fabric texture can interact with scan direction. If the grain dominates the portrait, test rotating the image or changing scan angle if your machine supports it safely.
Finish the material properly
Cleaning and finishing can change contrast. Wood may need brushing and sealing. Slate can look different after washing. Acrylic may need paint fill, backing or lighting to show the photo clearly.
Final checklist before the full engraving
Use this list after the test crop looks good and before you commit to the full-size job.
Eyes readable, subject separated from background, shadows not crushed, highlights not empty, no obvious blur and no strong JPEG damage.
Correct Photo Type, sensible brightness/contrast/gamma/sharpness, one dithering method selected and output inspected with the magnifier.
Final millimeter width confirmed, height acceptable, pixel count realistic and DPI chosen for the material, not just for a sharper-looking number.
PNG or BMP downloaded, file name labeled with material/DPI/dithering and original photo kept for future versions.
Imported physical size confirmed, no accidental double dithering, no unwanted contrast changes and proper raster/bitmap mode selected.
Focus, lens, air assist, overscan, scan direction, bed position and material hold-down match the successful test crop.
FAQ
What does PhotoEngraving.online do?
It converts a normal photo into a laser-ready black-and-white raster image directly in your browser. You can crop the photo, choose Photo Type, adjust brightness, contrast, gamma and sharpness, set real engraving width, choose DPI, compare dithering methods, preview an approximate material look and export PNG or 1-bit BMP for laser software.
Are my photos uploaded to a server?
No. The photo processing happens locally in your browser. This is useful for private portraits and also makes it easy to test different settings without uploading your image to the server.
What DPI should I choose in the editor?
Start with 254 DPI for softer materials or faster tests, 300 DPI for many general photo jobs and 508 DPI for materials that can hold fine dots such as some acrylics, laminates, anodized aluminum and coated metals. Use Custom DPI when you know the exact line interval you want. The right value depends on the laser spot, material and final physical size.
What does Negative Photo Type do?
Negative swaps black and white in the final output. Use it for dark materials such as slate, dark acrylic or black anodized aluminum, and for any surface where the engraved mark becomes lighter than the surrounding material. Use Normal Photo for light wood where burned areas become darker.
Which dithering method should I start with?
Start with Floyd-Steinberg. Try Atkinson when the result is too dark or you want a softer lighter look. Try Jarvis when the material can hold fine detail and you want smoother tones. Try Ordered/Bayer for logos, graphic-style work or a regular visible pattern.
Should I dither again in LightBurn, LaserGRBL, XCS or EZCAD?
Normally no. If the exported file from PhotoEngraving.online is already dithered, avoid applying another dithering algorithm in your laser software. Use pass-through or a true black-and-white workflow where possible.
What is the best image format for laser engraving photos?
Use PNG as the default final export because it is clean, widely supported and includes DPI metadata. Use 1-bit BMP when your software or workflow prefers a strict black-and-white bitmap file.
Should I use grayscale or dithering for laser engraving?
Use dithering when you want PhotoEngraving.online to create the final black-and-white dot pattern before import. Grayscale workflows can work too, but they depend more on laser software, power modulation and material behavior. Do not use both workflows at once.
Why does my laser engraving photo look too dark?
The common causes are too much laser energy, crushed shadows, too much contrast, high DPI on a soft material or dot gain. Try lighter gamma, lower contrast, Atkinson dithering, lower DPI, faster speed or less power.
Is Material Preview the file I download?
No. Material Preview is an approximate visual simulation only. It helps with inversion and rough contrast decisions, but the downloaded PNG or BMP remains the clean black-and-white laser-ready output.
Does the PNG or BMP include DPI information?
Yes. PNG and 1-bit BMP exports include DPI metadata so compatible software can preserve the intended physical size more easily. Still, always confirm the millimeter size after import because some programs ignore or reinterpret metadata.
Can I use my own DPI value?
Yes. Use Custom DPI when you know the exact line interval you want or when your machine/material test shows that a value between the presets works better.
Why does the preview look better than the engraving?
A screen is bright and smooth. Real engraving depends on heat, smoke, grain, coating, focus and material response. Use the preview to prepare the file, but trust a small test crop on the real material before the full job.
Why did live preview pause?
The selected output is very large. Reduce the physical width, lower DPI or crop tighter for a faster preview. If the large size is intentional, use export after confirming that your browser and laser software can handle the raster size.
PNG, BMP, JPG or SVG?
Use PNG as the default final export. Use 1-bit BMP when your software or workflow prefers a simple black-and-white bitmap file. JPG is acceptable as a source photo if it is high quality, but avoid repeated JPG exports. SVG is mainly for vectors, not final dithered photo pixels.
Research sources and further reading
This guide is written for the PhotoEngraving.online editor, but it also follows practical documentation from laser software and machine manufacturers. Use it as a working guide and always compare it with the manual for your exact machine and material.
- LightBurn User Guide: Image Mode — image modes, negative image, pass-through, line interval, DPI, grayscale and dithering modes.
- LightBurn User Guide: Interval Test — finding a suitable line interval for a specific machine, material and lens.
- Trotec: choosing the right engraving resolution — material-dependent DPI and dot bleed.
- Trotec: raster algorithms — ordered dithering and error diffusion principles.
- Trotec: photo laser engraving tips — photo quality, controlled power and grayscale matrix testing.
- Trotec: glass engraving tips — glass preparation and engraving methods.
- LaserGRBL: dithering tool — 1-bit dithering for materials that do not react linearly to power.
- LaserGRBL: line-to-line tool — grayscale line engraving and power modulation notes.
- xTool: material processing guide — grayscale, dithering algorithms and material behavior.
- xTool: preparing a photo for laser engraving — photo preparation, resolution, contrast and grayscale workflow.
- xTool F1 bitmap parameters — dot duration, power, DPI and laser source selection.
- xTool: plastic safety guide and Trotec: unsuitable materials — material safety warnings.
- OMTech: diode vs CO2 vs fiber lasers — practical differences between laser sources and materials.
Prepare your photo for engraving
Use PhotoEngraving.online to upload your photo, crop it, choose Photo Type, tune contrast, set the real physical width, choose DPI, preview dithering and material behavior, then export a laser-ready PNG or 1-bit BMP. Confirm the result on your real material with a small test crop before engraving the full piece.