Nine shells we make every season, each shown three ways: the long exposure, the cut through its equator, and the numbers. Sizes are in gō — one gō is about three centimetres of shell.
- 01Peonybotan5 gōRound, trail-less stars that change colour half-way — red, then green.
- 02Chrysanthemumkiku5 gōCharcoal stars that draw gold petals, each tipped with blue.
- 03Willowyanagi7 gōHeavy charcoal stars that burn slowly and fall like branches.
- 04Palmyashi7 gōNine thick comets on a rising trunk.
- 05Crossette—5 gōSilver comets that crack into four at the top of their flight.
- 06Ring—5 gōStars laid on one circle only, so the sky shows a tilted ring.
- 07Strobetenmetsu5 gōWhite stars that fly dark, then blink.
- 08Kamurokamuro10 gōA dense, glittering crown that hangs in the air.
- 09Pistil Peonyshin-iri botan7 gōA peony with a second, smaller sphere of green inside it.
No. 01 · botan
Peony
Round, trail-less stars that change colour half-way — red, then green.
- Size
- 5 gō · 15 cm
- Opens
- ≈ 170 m across
- Breaks at
- ≈ 190 m
- Colours
- Red · strontium
- Green · barium
Every star is rolled green first and red over the top, so the whole sphere turns at the same instant. If one star was rolled a pass short, you would see it turn early — that is how we check our rolling.
Pack one like it on the bench →No. 02 · kiku
Chrysanthemum
Charcoal stars that draw gold petals, each tipped with blue.
- Size
- 5 gō · 15 cm
- Opens
- ≈ 170 m across
- Breaks at
- ≈ 190 m
- Colours
- Gold · charcoal & iron
- Blue · copper
The gold is charcoal burning off the outside of the star and leaving a tail of sparks; the blue is the last layer, near the seed. A peony has no tail; a chrysanthemum draws its own petals.
Pack one like it on the bench →No. 03 · yanagi
Willow
Heavy charcoal stars that burn slowly and fall like branches.
- Size
- 7 gō · 21 cm
- Opens
- ≈ 220 m across
- Breaks at
- ≈ 250 m
- Colours
- Gold · charcoal & iron
Bigger stars, a slow composition and a gentle break, so they leave the shell slowly and hang. In a long exposure they are still burning when they reach the tree line.
Pack one like it on the bench →No. 04 · yashi
Palm
Nine thick comets on a rising trunk.
- Size
- 7 gō · 21 cm
- Opens
- ≈ 220 m across
- Breaks at
- ≈ 250 m
- Colours
- Gold · charcoal & iron
- Silver · titanium
Few, large stars packed with glitter. The trunk is the shell's own rising tail, a comet stuck to the outside of the shell that burns all the way up.
Pack one like it on the bench →No. 05 · western name
Crossette
Silver comets that crack into four at the top of their flight.
- Size
- 5 gō · 15 cm
- Opens
- ≈ 170 m across
- Breaks at
- ≈ 190 m
- Colours
- Silver · titanium
- Green · barium
Each comet carries a small splitting charge in a cross cut into its core. When the burn reaches it, the comet breaks into four children at right angles to its flight.
Pack one like it on the bench →No. 06 · western name
Ring
Stars laid on one circle only, so the sky shows a tilted ring.
- Size
- 5 gō · 15 cm
- Opens
- ≈ 170 m across
- Breaks at
- ≈ 190 m
- Colours
- Violet · strontium + copper
- Yellow · sodium
Stars on the equator and nowhere else, with a small yellow heart. Which way the ring tilts depends on how the shell turned in the mortar — nobody chooses it.
Pack one like it on the bench →No. 07 · tenmetsu
Strobe
White stars that fly dark, then blink.
- Size
- 5 gō · 15 cm
- Opens
- ≈ 170 m across
- Breaks at
- ≈ 190 m
- Colours
- Silver · titanium
The strobe composition pulses as it burns, several times a second. The eye sees twinkling; a long exposure turns each star into a dotted line.
Pack one like it on the bench →No. 08 · kamuro
Kamuro
A dense, glittering crown that hangs in the air.
- Size
- 10 gō · 30 cm
- Opens
- ≈ 320 m across
- Breaks at
- ≈ 330 m
- Colours
- Gold · charcoal & iron
- Silver · titanium
Named after a traditional bobbed hairstyle. More stars than a willow, a tighter burn and heavier glitter — the crown holds its shape for a moment before it falls.
Pack one like it on the bench →No. 09 · shin-iri botan
Pistil Peony
A peony with a second, smaller sphere of green inside it.
- Size
- 7 gō · 21 cm
- Opens
- ≈ 220 m across
- Breaks at
- ≈ 250 m
- Colours
- Yellow · sodium
- Orange · calcium
- Green · barium
The pistil is a second ring of stars laid around the burst charge, inside the first. Thrown more gently, it opens as a smaller green sphere at the heart of the yellow-to-orange one.
Pack one like it on the bench →