Whirls
Pursuit polygons spiralling inwards, alone or tiled with alternating chirality.
Pens
Colors follow pursuit depth, including in a single cell. Starts with 4 pens and works with anywhere from 1 to 8.
Settings
Layout, Sides, Edge length (mm), Direction, Step (t), Steps (0 = auto), Stop at radius (mm), Style, Cell outlines.
The preview uses the default settings on A4. Press R in the app for random variations. The SVG export is in millimetres with one Inkscape layer per pen, so it works with the AxiDraw extension, vpype and saxi.