Celtic Knot Shapes

Upload an SVG of a shape (a cross, a circle, a shield, a letter) and the knotwork is woven to fill it. Click a dot to add a break, click again to turn it, a third time to remove it. Download the result as an STL for printing or casting.

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Scroll to zoom, drag to move. Esc to finish.

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Drag to turn, right-drag to move, scroll to zoom.
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Shape

The shape is whatever the SVG draws: filled areas and lines alike. If it's a line drawing of an outline, tick Fill inside closed lines.

Layout

Breaks

One strand adds breaks until the whole knot is a single strand, then sprinkles in more where they keep it that way. Random just sprinkles. Mirrors and turns shape both; with them on, a few strands may remain.

Mirrors copy each break you click across the middle of the shape. Shift-click changes one dot at any time.

Strands

Carved: flat-topped strands with the background cut away in sloping facets, like the carved ring. Width sets the flat tops; about 0.3 mm suits it.

3D and export

For Blender: install make_knot_shape.py as an add-on, then Copy for Blender and choose Add > Mesh > Celtic Knot Shape. It builds the same design at full detail, with a fused print solid and the exact weight.

The STL is in millimetres. Strands overlap where they cross; slicers and casting services merge them, and Blender can join them with a Union.