Theme and Sketch
First, a theme is decided upon (historical figures, for example). When the concept comes together, a pencil sketch is made, and then color is added. Ample time is spent on the sketch, as it will serve as the blueprint for the nebuta.
The float is built and (once complete) stored in a shed called a nebuta-koya. These sheds are about 12 meters wide, 12 meters deep, and 6-7 meters high.
Smaller parts (face, limbs, weapons, and so on) are prepared ahead of time. A mathematical expression is used to calculate the dimensions and ensure everything is in proportion. Work on these sections continues right up until preparations for the shed begin.
At last the time comes to assemble the nebuta. Wires and cords are shaped around a framework of rectangular wooden beams to give the float a rough form. Bamboo was used instead of wire until about 1955.
Lighting and Electrical Wiring
The float is illuminated by 800-1,000 lightbulbs and fluorescent lights (candles were used in the past), all installed by professional electricians. The lights are powered by generators, and range from 20-100 watts.
Hoshogami paper is glued to the float's completed framework, with extra care taken to ensure nothing juts out (this is the most difficult part). At this point, the structure really starts to look like a nebuta!
Facial features, body parts, accessories (collars, sashes, and so on), and other details (such as kimono patterns) are drawn in black ink. The nebuta is still plain white at this point. The brushwork is always very impressive!
Melted paraffin is used to draw additional patterns onto the nebuta, in line with the desired expression. Aside from adding some brightness to the float, the paraffin also helps prevent color bleed.
The remaining white areas are colored in, using dyes and water-based pigments (they are brushed or sprayed on). The nebuta is now complete!
40-50 people raise the nebuta onto a decorated platform around 2 meters high (bringing the float's total height to about 5 meters). This is an emotional moment for all involved in the nebuta's construction.