The tool traces the outline of your artwork. Some images trace beautifully and some fall apart, and the difference is predictable.
What traces well
- Solid black on white. A silhouette with no shading.
- A transparent PNG where the artwork is the opaque part.
- An SVG with filled shapes. These are the best input by a wide margin, because there is nothing to guess at. The outline is already exact.
- Bold, chunky shapes with no line thinner than about 1 percent of the overall width.
What fails, and why
Photographs
A photograph has no clean boundary between subject and background. Tracing finds edges everywhere. Remove the background first, or use a silhouette instead.
Drop shadows and gradients
A shadow is a soft edge, so the trace does not know where the shape stops. Our tracer picks a threshold automatically using Otsu's method, which looks at the actual distribution of light and dark in your image rather than assuming a fixed midpoint, and it handles moderate shadows. A heavy drop shadow will still trace as a second outline around the subject.
Fix: delete the shadow layer, or flatten onto white with the shadow removed.
Anti aliased edges at small sizes
If you upload a 60 by 60 pixel PNG, the edges are mostly grey pixels. Upload at 500 pixels or more across, or use an SVG.
Line art
An outline drawing traces as two lines, an outer and an inner, so you get a cutter that cuts a ring rather than a shape. If you want the shape, fill it in. If you actually want the ring, that is what it will give you.
Very thin strokes
Anything under about 0.8 mm at your chosen print size cannot be printed. See what size should a cookie cutter be for the three ways out.
SVG specific notes
SVG is the best input, with two things to know.
- Open paths get stroked. A line with no fill is treated as a line of the stroke width it declares, so a signature or a line drawing comes through as a ribbon rather than being ignored or filled in.
- Overlapping shapes are merged, not cancelled. If your SVG has two overlapping filled circles, you get a peanut, not a peanut with a hole in the overlap.
The settings that change a trace
- Threshold. Chosen automatically. Override it if the automatic pick has gone wrong, which usually looks like the shape being noticeably fatter or thinner than the artwork.
- Smoothing. Rounds off the pixel staircase. Turn it up for a photo derived silhouette, down for a shape with deliberately sharp corners.
- Minimum feature size. Drops specks. Turn it up if a scanned image is giving you dust particles as tiny extra cutters. Turn it down if it is eating something you wanted, like the dot on an i.
- Simplification. Reduces the number of points. Useful for a very detailed trace that is slow to preview. Too much of it visibly flattens curves.
A shortcut worth knowing
If your design is a common shape, check the Pre made tab first. There are 169 shapes there, drawn as clean geometry rather than traced from an image, so they have no tracing artefacts at all and no minimum size problems beyond the blade itself.