Convert PNG to STL
Turn a PNG silhouette into a solid STL you can print, at a width you choose in millimetres. The image is thresholded to a shape, not read as a height map.
Turn an SVG outline or PNG silhouette into a solid relief. Your file stays in your browser.
What this keeps and what it drops
Kept
- The shape your brightness threshold separates, holes included
- The proportions of the image, scaled to the width you set
Dropped
- Colour, which an STL cannot store
- Everything between solid and empty; each pixel is one or the other
- Detail finer than the 256 pixel trace, and smooth edges with it
You set the width and the thickness, so there is no single result to measure. What is fixed is what the tool refuses, and it refuses rather than dropping quietly.
What this does
The tool separates your image into filled and empty by brightness, traces the boundary between them, and extrudes the filled part to a thickness you set. You choose the width in millimetres, the relief thickness, and whether the shape sits on a backing plate.
The brightness threshold is yours to set, from 0 to 255. Everything darker than it becomes solid, and you can invert that if your artwork is light on dark. Fully transparent pixels never count as solid whichever way round you work.
This is not a lithophane
A lithophane varies its thickness pixel by pixel so a photograph appears when light shines through it. This tool does not do that. It makes one decision per pixel, solid or not, and every solid part comes out the same height.
If you came here with a photograph hoping for a portrait you can backlight, this is the wrong tool and it will give you a black blob. Look for a lithophane generator instead.
What gives a good result
High contrast art with a clear edge: a logo, a stencil, a signature, a silhouette. Anything where you can point at the boundary and say the shape ends there.
Photographs do not, because there is no single brightness that separates the subject from the background. Neither do gradients, soft shadows, or drop shadows behind a logo.
The resolution to expect
Your PNG can be up to 4 million pixels and 8,192 pixels on a side. The trace itself runs at 256 pixels on the longest edge, and the outline follows the edges of those pixels, so it is stepped rather than smooth. On a 100 mm wide print each step is about 0.4 mm, which you can see and feel.
If you have the artwork as vector, use SVG to STL instead and the edges come out clean at any size.
Limits
PNG images are limited to 4 million pixels and 8,192 pixels on either side, and the silhouette is traced at 256 pixels on the longest edge. Only PNG is read; JPEG and other raster formats are not.