How to turn a photo or image into an STL

There are two ways to turn a photo or image into a printable STL, and picking the right one is the whole game. You can map brightness to height so the picture becomes a relief you light from behind — a lithophane — or you can trace the outline and extrude it into a solid shape like a cookie cutter or a stamp. Both run in your browser from an ordinary image, no CAD required. Here's how each works and which to choose.

Two ways to go from image to 3D

• Brightness → height (heightmap). Each pixel's lightness sets how thick the model is at that point. Dark areas print thicker, light areas thinner — perfect for a photo that reveals itself when backlit.
• Outline → extrusion. The image is reduced to a silhouette (by a brightness threshold), then that shape is given height to become a solid — a cutting blade, a raised stamp, or a framed panel.

A full-color photo can't print as color on most machines, so both methods work from the image's tones and shapes, not its colors.

Prepare your image

A little prep goes a long way:

• High contrast — a clear subject that stands out from the background traces and reliefs far better than a flat, busy photo.
• Decent resolution for heightmaps — more pixels means smoother gradients in a lithophane.
• A clean silhouette for outline work — simple shapes, no fine background clutter.
• Crop tight to the subject so detail isn't wasted on empty space.

Pick the tool for what you're making

3DGEN turns your image into the right kind of model in the browser — your photo never leaves your device:

• Lithophane generator — the brightness-to-height path. Turns a photo into a backlit relief plate; see how to make a lithophane from a photo.
• Cookie cutter generator — traces a silhouette into a cutting blade; see how to make a custom cookie cutter from any image.
• Stamp generator — traces a logo or photo into a raised relief stamp with a handle.

Set height and export

The one thing an image can't specify is depth, so you set it: the max/min thickness of a lithophane, the blade height of a cutter, or the relief height of a stamp, plus the overall size. Preview, then export STL (works everywhere) or 3MF (keeps units; great with Bambu Studio) — see STL vs 3MF.

Image vs vector — which input?

A photo or PNG/JPG is a raster image (a grid of pixels); the tools trace or height-map it. If you already have clean vector art, an SVG gives sharper outlines for cutters and stamps — see SVG to STL. Use a photo for lithophanes and quick traces; use an SVG when you want the crispest edges.

Tips for a clean result

• For lithophanes, choose a high-contrast portrait or landscape and print in white PLA.
• For cutters and stamps, keep the silhouette bold — thin necks and tiny islands print fragile.
• Boost contrast or invert the image if the trace grabs the wrong part.
• Preview at your real print size to catch detail that vanishes when small.

FAQ

Can I 3D print a photo in color?

Not as color on most printers. Instead the photo becomes a relief (a lithophane) that shows the image through thickness and light, or a traced silhouette shaped into an object.

What image works best?

High-contrast with a clear subject. For lithophanes use a good-resolution photo; for cutters and stamps use a clean, bold silhouette.

Photo or SVG?

Use a photo for lithophanes and quick traces. Use an SVG when you want the sharpest outlines for a cutter or stamp.