This free bas relief generator turns a photo, logo, or drawing into a 3D relief STL with a flat back. Upload an image, choose how brightness becomes height, and download a file for your slicer, CAD app, or CNC software.

Why turn an image into a 3D relief?

A bas-relief (also called a low relief) is artwork that rises a little from a flat background, like the design on a coin. It works well for wall plaques, signs, logo badges, ornaments, and gifts that are seen from the front. You can print it face-up with its flat back on the build plate, then paint or dry-brush the raised detail. The same image can also give you contour lines or a grayscale heightmap for other design work.

What does image to STL conversion keep and lose?

The tool resizes your image to a grid of height samples, and each sample sets one height. Quality decides how fine that grid is: Low uses 320 samples along the longest side, Medium uses 600, High uses 900, and Extra high uses 1500. More samples keep smaller detail, like thin lines and small lettering, but make bigger files. Bright areas rise by default, and the Raise dark areas instead of bright option flips that. Contrast makes height changes stronger or softer. Smoothing evens out grain from photo noise but keeps strong edges sharp. Flatten lighting removes broad light and shadow, like a glowing background or a shadow across one side of a face, so the relief follows edges and detail instead of the lighting. The tool also adds a solid backing under the raised surface.

This is a brightness map, not a depth scan. A white shirt may rise higher than a dark face, even if the face was closer to the camera. Shadows can become grooves. The model does not keep the image's color, material, or texture, or any shape hidden behind the subject. Start with a clear subject and simple lighting, then check the 3D preview before printing.

How to turn a photo or logo into a relief STL

  1. Choose or drop an image

    Upload a photo, logo, or drawing. The tool builds a rectangular plaque right away with the default size and depth.

  2. Pick the outline

    Keep Plaque to use the whole image. For a logo or artwork on a plain or transparent background, choose Cutout, click the background in the image, and adjust the tolerance until the mask keeps what you want.

  3. Set the quality and relief

    Pick Low, Medium, High, or Extra high. Each option shows its sample size and about how big the STL will be. Set the size and depth in millimeters, then fine-tune the surface. The 3D preview updates on its own a moment after each change.

  4. Finish the plaqueOptional

    Trim the plaque to a rectangle, rounded rectangle, oval, or circle. Add a raised frame, a hole or nail slot for hanging, and a line of raised text such as a name or date.

  5. Inspect and download

    Rotate and zoom the preview to check the relief. Grid only shows or hides the build plate guide. Download STL, 3MF, or OBJ for the full-detail mesh, or choose Generate STEP for a faceted CAD file.

Plaque options for wall art and gifts

Shape trims the plaque to a rectangle, a rounded rectangle, an oval, or a circle. Circle uses the centered square of your image, and Longest side becomes the diameter. Border width adds a raised frame 0.4 mm taller than the highest relief, which protects the surface and gives the piece a finished edge.

For hanging, Hole cuts a 5 mm hole through the plaque near the top edge, for a ribbon, hook, or cord. Nail slot recesses a 12 mm slot into the back near the top, so the plaque hangs flush on a nail or screw head. The slot needs a backing at least 2.5 mm thick. Print the plaque face-up and the slot's ceiling prints as a short bridge.

Text line adds up to 40 characters of raised lettering on a flat label near the bottom. Text height sets the height of the capital letters. Long text shrinks to fit inside the plaque and border, and the tool tells you if it still cannot fit.

Choose the right download

  • STL: The full-detail, closed mesh, with coordinates in millimeters. Open it in your slicer.
  • 3MF: The same full-detail mesh in a compressed file, often a fifth the size of the STL. Bambu Studio, OrcaSlicer, and PrusaSlicer open it directly, and the file declares millimeters.
  • OBJ: The same mesh as the STL, without the image as a texture. Edit it in a modeling app.
  • STEP: A lower-detail faceted solid. Import it into a CAD app.
  • 16-bit PNG: A grayscale heightmap of the relief, with black outside a cutout. Use it for CNC carving or other heightmap workflows.
  • SVG: The outer edge and contour lines at every 10% of the relief height. Edit or trace the 2D lines.

STL and OBJ files do not store units, so this tool writes their coordinates in millimeters. Check the imported size in your next app. STEP declares millimeters but does not gain editable sketches, curves, or feature history from the image. The PNG and SVG are 2D files, not ready-to-print solids.

Using the heightmap for CNC carving

If you carve wood or foam on a CNC router, the 16-bit PNG may be more useful than the STL. In the heightmap, white is the highest point of the relief and black is the lowest. The backing is not included. Because it uses 16 bits, it holds 65,536 height levels instead of the 256 in a normal grayscale image, so gentle slopes carve smoothly instead of in small steps.

Many CAM programs, including Vectric and Carveco products, can build a 3D relief from a grayscale image or import the STL directly. A PNG does not tell that software how deep to cut, so set the depth yourself. Match it to the Relief depth you chose here, plus 0.4 mm if you added a border. The tool also writes the depth and longest side into the PNG's description text, if you need a reminder later. If your software only reads 8-bit images, it may reduce the height levels and show faint steps.

For a cutout, the lowest part of the relief is also black, the same as the background. Use the SVG outline as your cut boundary instead of tracing the heightmap.

Common problems and quick fixes

  • Fine detail looks soft. Choose High or Extra high quality. Extra high is best on a desktop computer, since each update takes several seconds. Small lettering and thin lines need more samples to survive.
  • The file is too big for your slicer or upload. Download the 3MF instead, or choose Medium or Low quality. A 100 mm plaque at High can pass 60 MB as an STL but stays near 10 MB as a 3MF.
  • The subject looks faint or sinks into the background. A bright background or glow is being raised above the subject. Raise Flatten lighting to 50 to 80%, or turn on Raise dark areas instead of bright for a dark subject on a light background.
  • The face looks uneven. Strong lighting and cast shadows become height changes. Try Flatten lighting, a more evenly lit photo, less Contrast, or more Smoothing.
  • The nail slot or hole shows an error. The slot needs a backing at least 2.5 mm thick, and both need room inside the border. Increase Backing thickness or Longest side, or narrow the border.
  • The background stays in Cutout. Click a clean area of the background and raise Background tolerance a little. This color-based removal works best on solid backgrounds. Busy scenes may need image editing first.
  • Part of the subject disappears. Lower the tolerance or pick a different background point. Check the mask before downloading.
  • The cutout has loose pieces. Separate areas of an image can become separate printable pieces. The tool reports the piece count. Use Plaque mode when everything must stay connected.
  • The STEP file looks less detailed. Its mesh is reduced on purpose to keep the CAD file manageable. Use STL or OBJ when fine surface detail matters.

About the input and output

PNG, JPG, and WebP are picture formats. They can show color, but none of them tells the tool how far a photographed object really extends in space. Transparency in a PNG or WebP can give Cutout a clean outline. A JPG has no transparent edge, so a simple background color is easier to remove.

STL and OBJ describe the raised shape as triangles. The printable files include a flat back, while the heightmap and contour SVG describe the relief in two dimensions. STEP stores a faceted CAD solid built from a reduced version of the mesh. None of these exports recreates a fully sculpted, all-sides model from a single photo.

What to do next

Open the result in the Free Online STL Viewer with Measurements to check its size and raised detail. Then load the STL in a full slicer and inspect the layer preview before printing. For a simple browser slicing workflow, try the Free STL to Gcode Converter.