EZCAD: 1-Bit BMP or SVG for Fiber Laser Marking?
EZCAD accepts both bitmaps and vectors, and which one you should use is not obvious from the interface. The short answer is that it depends on whether you are marking filled areas or following lines — and that EZCAD's vector import is fussier than most people expect. This covers both routes, how to prepare files for each, and which to choose for a given job.
How EZCAD Treats the Two Formats
EZCAD drives a galvo scanner: two mirrors steering a beam. It has two fundamentally different ways of covering an area, and the file format determines which one you get.
Bitmap import (BMP). EZCAD scans line by line, firing the laser where pixels are dark. This is raster marking, and it is how photo-style marking works. A 1-bit BMP — pure black and white, no greys — removes all ambiguity: every pixel is either mark or skip. Greyscale bitmaps get converted internally with dithering settings you have less control over.
Vector import (DXF, AI, PLT, SVG in newer builds). EZCAD follows the paths. Curves become continuous beam movement, which produces genuinely smooth lines rather than stair-stepped raster approximations. Fill is applied via hatch, calculated by EZCAD from the closed shapes.
The distinction that matters: a bitmap encodes what to mark, a vector encodes where to move. For photographic content the first is right; for outlines, text and cut-like marking the second is far better.
When to Use a 1-Bit BMP
Use a bitmap when the content is photographic or tonal:
- Portraits and photo marking on stainless, anodised aluminium or coated metal.
- Textures and patterns that have no meaningful outline.
- Anything already dithered where you want exact control over which pixels fire.
Preparing a 1-bit BMP properly:
- Convert the photo to line art or a dithered black-and-white image first — the EZCAD converter exports 1-bit BMP directly, which avoids the usual round trip through an image editor.
- Size it to the final marking dimensions in pixels. Match your intended marking resolution: at 600 DPI, a 40 mm wide mark is about 945 pixels. Oversized images are downsampled by EZCAD with results you did not choose.
- Save as BMP with 1-bit colour depth, uncompressed. Not greyscale, not 8-bit indexed, not RLE-compressed.
- In EZCAD, place the image and check "Fixed DPI" so it does not rescale unpredictably.
The single most common problem here is importing a 24-bit BMP or a JPEG and letting EZCAD threshold it. The result is unpredictable across machines and versions, because you have handed the most important decision to a dialog you are not watching.
When to Use a Vector
Use a vector when the content has real geometry:
- Logos, text and serial numbers — edges stay genuinely sharp at any size.
- Line art where you want the beam to follow strokes rather than scan across them.
- Deep engraving with multiple passes, where hatch fill and consistent path following matter.
- Anything to be marked at several sizes from one file.
Preparing vectors for EZCAD:
- Convert all strokes to filled paths. EZCAD's hatch works on closed shapes; open strokes may mark as single hairlines or be ignored entirely.
- Convert text to outlines. Fonts do not travel.
- Ensure paths are closed. Small gaps break hatch fill, producing partially filled shapes.
- Simplify. Galvo systems slow down at every node; a path with 50,000 nodes marks slowly and can stutter visibly.
- Export as DXF if SVG import misbehaves — older EZCAD builds have patchy SVG support, and DXF remains the most reliably imported vector format.
Hatch settings are where vector marking is won or lost. Line spacing of 0.01–0.05 mm suits most filling; the cross-hatch and bidirectional options substantially affect both appearance and time. Test on scrap before committing.
Quick Decision Table
| Job | Format | Why |
|---|---|---|
| Photo portrait on stainless | 1-bit BMP | Tonal content; raster scanning is the right mechanism |
| Company logo | Vector (DXF) | Sharp edges, scalable, clean hatch fill |
| Serial numbers, text | Vector or EZCAD text | Crisp at small sizes; EZCAD generates text natively |
| Line art drawing | Vector | The beam follows lines instead of scanning across them |
| Deep engraving | Vector | Multi-pass hatch with consistent path following |
| Texture or pattern fill | 1-bit BMP | No meaningful geometry to follow |
| Silhouette or solid shape | Vector | Hatch fill is faster and cleaner than raster scanning |
Marking Parameters Worth Knowing
Format choice interacts with parameters, so a few notes specific to each.
For bitmap marking, the parameters that matter most are speed, power, frequency and the Y-axis step (line interval). A step finer than your beam spot wastes time without adding detail; on a typical 20W fibre with an F-theta lens the spot is roughly 0.03–0.05 mm, so a step below 0.02 mm is usually pointless.
For vector marking, hatch spacing plays the equivalent role, plus two settings that catch people out: Delay parameters (laser on/off, mark and jump delays) determine whether corners come out sharp or rounded, and whether lines have burnt-in start points. If your marks have heavy dots at the beginning of each line, the laser-on delay is too long.
For both, frequency changes the character of the mark substantially on metals — a lower frequency deposits more energy per pulse and cuts deeper, while a higher one produces a smoother surface mark. Colour marking on stainless depends on it almost entirely. The settings cheat sheet has starting values for common metals.
Frequently Asked Questions
Why does EZCAD prefer a 1-bit BMP over a JPEG?
A 1-bit BMP has already answered the only question that matters — mark or skip — for every pixel. A JPEG has millions of colours plus compression artefacts, so EZCAD has to threshold it internally using settings you are not directly controlling. The results vary between machines and software versions, while a 1-bit BMP marks identically everywhere.
Can EZCAD import SVG files?
Newer builds do, but support is inconsistent across versions and some features are silently ignored. DXF remains the most reliably imported vector format for EZCAD. If an SVG imports with missing shapes or broken fills, converting it to DXF usually resolves it without any other change.
What resolution should my BMP be for fiber laser marking?
Match it to the physical marking size and your intended DPI. At 600 DPI a 40 mm wide mark needs roughly 945 pixels. Substantially oversized images get downsampled by EZCAD in ways you did not choose, and undersized ones show visible pixel steps. Sizing correctly before import gives predictable results.
Why are my vector marks not filling in completely?
The paths are not closed. EZCAD's hatch fill needs genuinely closed shapes, and a gap of even a fraction of a millimetre breaks it. Check for open paths in your vector editor and close them before export. Unconverted strokes cause the same symptom — convert strokes to filled paths first.
Should I use a bitmap or vector for engraving a photo on metal?
A 1-bit BMP. Photographs are tonal content with no geometry to follow, so raster scanning is the correct mechanism. Convert the photo to a dithered or line-art black-and-white image at the final marking size first, rather than letting EZCAD threshold a colour photo on import.