Brain candle mold

A brain candle 98 mm long and 54 mm tall, with the winding folds, the temporal lobe and the cerebellum underneath: the side view the brain emoji shows. A Halloween favourite, and the perfect gift for anyone who just had a big-brain idea.

The mold is exactly what our two-part candle mold generator builds for it: two rigid halves with rubber-band grooves, pry pockets and a pour funnel on top. The seam runs between the two hemispheres, so each half is one side of the brain and the folds on both sides come out as sculpted. The tool's own seam check finds nothing stuck, and you need no silicone.

Pour it in pale pink for anatomy, grey for zombie, or a translucent wax for something stranger. The zip carries both halves, the brain master as its own STL, the tool's own print-settings sheet and a recipe file for the generator.

Shown as a 3D render of the printed mold halves pulled apart around the candle they cast, not a photo.

What you need

• About 264 g of pillar wax: the cavity holds 293 ml
• A tabbed, primed wick for a 70 mm candle, about 75 mm long
• Rubber bands or clamps, and a clip or wick bar across the funnel

How to cast it

1. Print both halves as exported. Clamp-strength settings: 4 walls, 40% gyroid infill, no supports.
2. Drop a tabbed wick into one half so the tab sits on the cavity floor, close the halves and band them along the whole seam.
3. Clip the wick centred across the pour funnel and pour at 65 to 75 C.
4. Once the first pour is firm but still warm, top up the funnel. Wax shrinks, and the second pour fills the dip.
5. Cool fully, open the halves at the pry pockets and trim the wick. A soft brush of red or grey mica in the folds brings them out.