Tomoshibi

What is Tomoshibi?

Tomoshibi generates the forming mold that a washi paper lantern is built on. You draw the lantern's cross-section in a section editor by dragging control points, starting from an egg, barrel or flat round template, and the app builds the mold parts to match: radial ribs that carry the lamp curve and grooves for bamboo, two hubs that hold the ribs, a stand to turn the mold while you work, and two opening rings that stay in the finished lantern.

The panel sets body height, rib count, board thickness, bamboo diameter and pitch, an optional spiral winding and leg sockets on the bottom ring. Four views show the section, the assembled mold, the parts laid out on your print bed and the lit lantern. Export is one ZIP with the STL parts, a full-scale A4 PDF template for cutting the washi panels and a JSON backup of the design. Without a printer, a cardboard mode gives A4 cutting templates for the same mold instead.

The craft part is yours: wind bamboo rods into the grooves, paste the washi over them, let it dry, pull the mold out through the openings and fit your own light. The in-app build guide walks through each step. It is free, runs in the browser without an account, and the interface is in English or Japanese. The code is MIT licensed, and selling printed molds and original lanterns made with them is welcome. Tomoshibi is meant for designs of your own: the maker does not encourage copying existing products. It suits makers who want a paper lamp in a shape of their own and do not mind some handwork.

What you can make

• Washi lantern forming molds
• Ribs with bamboo grooves and two hubs
• A mold stand and opening rings
• Full-scale washi panel templates

How to use Tomoshibi

1. Pick the egg, barrel or flat round template
2. Drag the points in the section view and set rib count and bamboo size
3. Open the Print view, set your bed size and export the ZIP
4. Print the parts, assemble the mold and follow the build guide