Mon Mai (Folding Wooden Pillow) — a 3-5 × 10-15 × 20-25 cm Hardwood Plank Split into Two Leaves Joined by 5-6 Interlocking Tenons; Set Crosswise, Folds Flat

"Once the tenons are cut on both sides of the plank, it separates into two leaves, held together by the tenons that were cut." (Sirindhorn Anthropology Centre, author พิชชา ทองขลิบ (Phitcha Thongkhlip), CC BY 4.0)

Use a hardwood such as chingchan, makha, daeng, pradu or teak. Cut an already-sawn plank 3-5 cm thick, 10-15 cm wide and 20-25 cm long. Plane both faces smooth.

Split the plank (chak mai) from both ends into two leaves, but not all the way: leave about two inches in the middle. With a chisel cut about 5-6 interlocking tenons, alternating one by one and alternating sides of the plank, cut down to the split. Once both sides are cut, the plank separates into two leaves joined by the tenons.

Sand the surface smooth with sandpaper; in the old days stingray skin was used.

Photos of a real mon mai from the Wat Samrong Folk Museum (Sirindhorn Anthropology Centre, author พิชชา ทองขลิบ (Phitcha Thongkhlip), CC BY 4.0)

For use, set the two leaves crosswise; for storage, fold them flat into one plank. Elders often lay a sabai or pha khao ma over it so it does not hurt. It also serves as a book rest.

During Buddhist Lent, elders make merit, chant and keep the precepts at the temple on every holy day, resting in the sala or the ordination hall after the midday meal, so the wooden pillow was made for them. Take care with the chisel when cutting the tenons. Source: Sirindhorn Anthropology Centre, Traditional Objects of Everyday Use database, "หมอนไม้", author พิชชา ทองขลิบ (Phitcha Thongkhlip), Wat Samrong Folk Museum, Nakhon Pathom (CC BY 4.0 licence). **Limits** The source gives no size for each tenon and does not name the tool used to split the plank.