Guide

How to prepare an image so it traces into a clean cut file

Every tracer, whether it is Design Space, Inkscape, Silhouette Studio or Cutline, follows the pixels it is given. Most bad cut files come from the image, not the tracer. Ten minutes on the image saves a sheet of vinyl.

1. Start from the biggest, cleanest original

A tracer can only follow edges that exist. Work out how many pixels you have for each inch you will cut:

The more pixels per inch of finished width, the smoother the curves. A common rule of thumb is 150 to 300 pixels per inch of the size you will cut. Below about 100, curves get visibly steppy on a large cut. Upscaling a small image doesn't add real edges, so look for a bigger original first.

2. Prefer PNG over JPG

JPG compression leaves faint blocks and halos around sharp edges, which turn into specks and wobbly outlines. If the only copy is a JPG, use the largest one and expect to raise the speck size. A PNG with a transparent background is best of all: the background is already gone.

3. Flatten the colors

Count the colors you will actually cut. Shadows, gradients, glows and textures each become extra pieces. In any editor, fill each area with one flat color, or trace with fewer colors than the image appears to have and let the small differences merge. For vinyl, every color is another mat to cut and weed.

4. Photos of drawings: fix light and contrast

• Shoot straight down in even daylight, with no shadow from your phone across the page.
• Crop to the drawing. Paper edges and the table become shapes.
• Raise contrast until the paper is white and the lines are black. Pencil drawings usually need inking over first.
• Trace in one color (silhouette or brightness cutoff) and move the threshold until the lines are solid but the paper texture is gone.

5. Thicken what is too thin to cut

A tracer will happily trace a hairline that no blade or weeding hook can handle. Very thin lines and tiny lettering tear when you weed, and a laser burns fine features away. Thicken lines in the image (or stroke them in a vector editor) before tracing, or cut the design bigger.

6. Do a test cut before the good material

Cut on scrap first and look at the smallest pieces. If they tear or fall out, raise the speck size, simplify, or cut bigger.

How the Cutline sliders map to this

• Colors: how many flat colors to trace. Fewer merges shadows and gradients.
• Speck size: drops specks and fills pinholes below that size, so there is no confetti to weed.
• Detail and Smoothing: how closely the outline follows the pixels, and how much it rounds pixel steps into curves.
• Drop background: removes the color touching the image edge, usually the paper.

The preview and the cut view are free, and so is a one-color test cut traced at 600 px, so you can try all of the above on scrap before paying $2 for the full files.