How big should the image be before tracing?

A tracer can only follow the edge that's in the image. If the edge is 3 pixels of blur, the traced outline wobbles inside those 3 pixels, and no curve fitting can know where the designer meant it to be.

A practical floor

For a logo or clipart, aim for about 1,000 pixels across the long side. At that size a typical letter stroke is many pixels wide, curves have enough steps to fit smoothly, and small details survive. Below about 500 pixels, text and fine lines start to lose their shape before tracing even begins.

Bigger isn't always better. Beyond about 1,600 pixels, Makerfern scales the image down before tracing. Past that point the extra pixels mostly add noise and time, not accuracy.

What Makerfern does with small images

Images under 900 pixels are enlarged with smooth interpolation before tracing. Enlarging doesn't add detail. It does give the tracer sub-pixel positions to work with along each soft edge, which produces noticeably smoother curves than tracing the tiny grid directly.

Where to find a bigger copy

• Ask for the original. Businesses almost always have a vector or a large PNG of their logo. A PDF export is also good.
• Look for the largest version online. The image in a website's header is often much larger than it's displayed.
• Avoid screenshots. A screenshot captures the screen's resolution, not the image's, and adds its own scaling blur.

JPEG quality matters as much as size

A large, heavily compressed JPEG can trace worse than a smaller PNG. Compression noise is concentrated at edges, exactly where the tracer is looking. If you have the same image as both, use the PNG.

Know when not to trace

If the source is tiny, blurry and important, like a client's logo for a paid order, tracing is the wrong tool. Get the original file, or have it redrawn. A converter should tell you that, rather than sell you a file that won't cut cleanly.