Convert an Image to a CNC Relief
Relief carving is one of the oldest CNC jobs, and a PNG is the perfect source: brightness becomes cutting depth. Export an STL and send it to your CAM software to generate toolpaths — no manual 3D modeling required.
Why images suit CNC relief
A raster image is already a depth field: light pixels cut shallow, dark pixels cut deep. The converter turns that field into a solid relief with a flat back, which is exactly the blank a CNC router wants before roughing and finishing passes.
Parameters that matter for carving
- Keep the relief modest (1–3 mm) so toolpaths stay clean and cycle times short.
- Use a hard edge (low edge subdivision) so the perimeter follows the bit precisely.
- Add a base plate — it becomes the stock surface your vise or clamps hold.
- Raise contrast for crisp line art and text engravings.
From STL to toolpath
Load the STL into your CAM (Fusion, VCarve, Carbide Create, etc.), set a roughing pass to clear the bulk, then a fine finishing pass across the relief. A ball-nose bit traces the curved surface best. Export G-code and run it on wood, aluminum, brass or acrylic.
Frequently asked questions
What relief height works for CNC?
For most signage and plaques, 1–3 mm reads clearly without long cycle times. Go deeper for bold sculptures, but watch your bit length and step-over.
STL or 3MF for CNC?
STL. CAM software consumes geometry, and color is irrelevant to a cutting toolpath, so STL is the right export.
Ready to try it? Convert your image to STL or 3MF in your browser — free, private, and with no sign-up.
Open the converter