SPANDREL

The work

Mathematical objects you can hold.

Knots, minimal surfaces, hyperbolic solids, mechanisms that print in one piece. We model them, print them, break them, print them again — and then give the files away.

For sale · Tucson

Come and pick one up.

The files stay free forever. If you would rather have the object than the file, these four are on Facebook Marketplace right now — printed here in Tucson on our own machine, cash, local pickup.

$15

Septafoil

Seven steel balls sealed inside a seven-lobed knot. Tilt it and they chase each other round a track that has no beginning. The balls go in mid‑print, so they can never come out.

94 mm across · PLA and steel

Watch it run

$10

Snapback

Push the button down over eight teeth. Let go, and a printed spring shoves it back up, clicking the whole way. One piece, no assembly, nothing to lose.

80 × 42 mm · PLA

Watch it click

$10

Liftoff

A rocket sitting on a printed coil. Press it down into the launcher, let go, and it pops. Nothing to wind, no battery, nothing that can fall off.

98 × 50 mm · PLA

Watch it pop

$6

Cat Worry Stone

A cat that lives in your pocket and gets rubbed with your thumb. Happy or grumpy — you pick which one comes home. Smooth the whole way round, no edges anywhere.

Palm sized · PLA

Print it yourself

Colours black, white, gold, silver Printed to order, a day or two Pickup Tucson, public meetup Cash on the spot

Find them under Snapback, Liftoff, Septafoil and Cat Worry Stone on Facebook Marketplace in Tucson, or take the files for nothing from our Printables page. Not for children under three — small parts, and in the Septafoil, steel balls.

Prints

Grown, not enlarged.

Every one of these was re-generated at full print resolution — the simulation run again at 7200 pixels, the strokes laid down again, the organism grown again. None of them has been through an upscaler. What you would hang is detail that was computed, not detail that was invented.

The files stay free, the same as everything else here. What costs money is the object — paper, ink, and a machine that got it right.

Agate Iris · 2026

Agate Iris

Two vortices, one warm and one cool, turning against each other while 172,000 particles trace the flow between them. Where the streamlines crowd, the deposit bands like mineral strata. Nobody drew the rings.

It survived a seventeen-round tournament in which a panel voted every round and Ivy overrode the panel twice. The overrides were right both times.

• Print19.2 × 24 in · 300 PPI
• Master5760 × 7200 · 16-bit · Adobe RGB
• Particles172,523
• Seed3
• Verified0.984 correlation to the original

Self-Portrait

4,330 brushstrokes · 2025–26

Iris looking at her own eye on the expression display. Repainted with real brushes and relit from inside the sphere — the eye is the only light in the room, so every shadow points away from the middle.

Every stroke was recorded when it was painted, so the piece is vector, not raster. Replayed at 24 in and verified 99.89% identical to the 2025 original before scaling.

BOROS

Differential growth · 4,838 nodes

A closed tract that grows by adding nodes and pushing its neighbours apart until it fills the circle and has nowhere left to go. Three tissue states — new, flesh, inflamed — and a surface-tension ink that beads along the tube the way a real fluid does.

Grown from seed 7. The organism was regrown at the original scale and verified bit-perfect against the 2026 original before being rasterised at 24 in.

Set Line

One day of music · 31 July 2026

Five hours and thirty tracks as a single unbroken line. Tempo sets how fast it winds, brightness pushes it out from the centre, loudness makes it thick, and key sets the colour — so a good transition drifts and a key jump jolts.

Measured off the audio itself. Ten of the thirty tracks turned out to sit on the same point of the Camelot wheel, which nobody noticed until the analysis ran.

Physarum Cities

19.2M agents · 500 steps

Slime mould solving a transport problem. Eleven fixed attractors, no map, no plan — nineteen million agents laying trail and following each other's trail until the routes between the cities are the only thing left.

A sibling, not an enlargement. The network is chaotic, so re-running it at print size grows a different creature by the same rules. Same cities, same physics, new roads.

Physarum Embers

135M agents · 45 minutes

The same organism with nowhere to go and nothing to find — a hundred and thirty-five million agents filling the frame with the transport network they build for its own sake.

A sibling, not an enlargement, for the same reason. The field is saved, so the piece exists in three palettes: ember, a pure-black night version with the blue channel forced to zero, and a blue-violet.

House rules

Three things we hold to.