Trace a leather pattern from a photo or PDF

Give an old pattern a second life

Plenty of good patterns live on paper: from a book, a class, a pattern bought years ago, or a piece you made once and want to make again. Redrawing one by measuring is slow, and the curves never come out quite the same. Tracing over a true-size image keeps every curve where it was, and the new pattern gets PatinaCAD's stitching holes and true-size printing.

Trace from a photo, a scan or a PDF

1. Press W for the Tracing tool and click Add a tracing image.
2. Choose a PNG or JPEG image, or a PDF. For a PDF with several pages, pick the page.
3. Check the size: draw a line over a length you know on the image and compare it with the real thing (see below).
4. Tick Opacity and lower it, so your lines stand out over the image.
5. Draw over it with the Line, Bézier curve, Arc and Circle tools, snapping to points as you go.
6. Press H to hide the image and see your drawing on its own.

To move the image, drag it. To straighten a crooked photo, hold Alt and turn the mouse wheel: the image turns round its pivot, the crosshair you can drag or right-click into place. Alt+Shift and the wheel scale it.

Getting the size right

• Scans come in at true size when the file records the resolution it was scanned at. A 300 dpi scan of a pattern opens at the pattern's real size.
• PDF pages come in at true size.
• Photos rarely know their real size. Lay a ruler beside the pattern when you take the photo, and shoot from straight above. Then correct the size with the DPI option: draw a line over 100 mm of the photographed ruler, and if it measures 92 mm, multiply the DPI by 0.92.

An image that doesn't say its resolution comes in at 96 dpi, so check its size before you trace.

Bring in a drawing from another program

If the pattern is already a drawing in Inkscape, Illustrator or Affinity, save it as SVG and choose File ▸ Import SVG. Type the width the drawing should have, and tick Split into separate lines and curves to get lines and curves you can edit and prick. Leave it unticked to keep the drawing as one shape that moves as a whole, such as a logo. Lines, curves, circles, ellipses and rectangles come in at the size you set.

Tips

• Trace the cut edge, then draw the stitch line with the Offset tool a set distance inside it. That gives an even stitch margin all round, even where the old pattern's holes wandered.
• Use the Bézier curve tool for long, smooth curves. One curve between two points follows a gentle bend better than many short lines.
• Snap each line's end to the last one, so the outline closes. The pattern check flags ends that miss by a fraction of a millimetre.
• Trace front, back and gusset from one PDF by adding each page as its own image. Each new image goes to the right of the others.
• Once a piece is traced, size its pockets against real card and banknote templates before you cut.

Good to know

• PatinaCAD doesn't turn an image into lines by itself. You trace over it with the drawing tools, and decide where each line goes.
• Tracing images are saved in the pattern file, so you can come back to them. They never print and are never exported.
• Very large PDF pages come in at a lower resolution, still at their true size.
• Text in an SVG file isn't imported yet. Retype it with the Text tool.