Fine-Grain Hinoki & Sugi Relief Openwork: Sukashibori Fret-Sawing

In the spatial philosophy of Japanese architecture, empty space is never an absence; it is an active, living presence known as ma. Nowhere is this metaphysical principle more brilliantly embodied than in the art of sukashibori (pierced openwork carving). Unlike Western classical relief, which fills space with dense, heavy figurative mass, sukashibori celebrates the void. By strategically removing timber from the transom panel, the master woodcarver transforms solid wood into a dynamic atmospheric lens.

When light filters through the pierced voids of a sukashibori ranma, the physical wooden members—whether representing soaring cranes, weeping willow branches, or geometric latticework—cast elongated, shifting shadows across the ceiling and floor of the adjacent room. The screen acts as an acoustic and visual veil: obscuring direct sightlines to preserve domestic modesty while permitting the subtle sounds of garden water fountains, seasonal breezes, and family life to flow unimpeded between contiguous spaces.

The mechanical feasibility of carving gossamer-thin openwork webs without structural breakage depends entirely upon the quality of the timber. For centuries, the undisputed standard for imperial and temple ranma has been Kiso Hinoki (Japanese cypress harvested from the Kiso Valley in Nagano Prefecture). Protected since the Edo period under strict forestry conservation edicts by the Owari Tokugawa clan (who famously declared 'one tree, one head' to punish illegal loggers), Kiso cypress grows on steep, rocky mountain slopes under severe cold and heavy snow.

These harsh conditions force the tree to grow with extreme patience, laying down tightly compressed, microscopic annual rings. Sawn strictly along the vertical radial planes into masame (quarter-sawn grain), the wood displays straight, parallel grain lines running continuously from top to bottom. Because the vascular fibers run in strict alignment without knots, wild grain, or tension zones, the artisan can carve structural webs as narrow as 1.5 millimeters without fearing that the wood will split along transverse fracture planes.

The technical instrument that makes sukashibori possible is the hikimawashi-nokogiri—a traditional narrow-blade piercing saw. While Western saws cut on the push stroke (requiring thick blades that resist compressive buckling), Japanese saws cut exclusively on the pull stroke. When pulled toward the craftsman's torso, the blade is subjected to pure tensile stress, allowing the blade steel to be ground to a fraction of a millimeter in thickness.

The artisan grips the long paulownia-wrapped handle with both hands, stabilizing the timber blank on a low wooden workbench. Pulling the saw along the sumi ink guidelines, the artisan applies gentle, rhythmic pressure. The razor-sharp impulse-hardened teeth slice cleanly through the soft springwood and dense summerwood bands with zero fiber tear-out. The narrow taper of the blade allows the craftsman to negotiate tight, continuous radius turns—carving the delicate rounded crests of ocean waves or the acute serrations of bamboo leaves with effortless fluidity.

Once the negative space is fully evacuated, the finishing process honors the ancient ethic of kizukuri—the art of revealing the innate spirit of timber without superficial coatings. Sandpaper is strictly rejected in master workshops: modern abrasive paper breaks off sharp wood fibers and fills the porous tracheids with dusty synthetic silica, deadening the natural color and optical luminosity of the wood.

Instead, the craftsman utilizes tokusa (dried scouring rush or horsetail reed, Equisetum hyemale). Harvested from mountain stream banks and dried in the shade, tokusa stems contain natural cylindrical deposits of microscopic mineral silica embedded within flexible cellulose walls. Lubricated with clean mountain water, tokusa burnishes the cut edges of the Hinoki, polishing the wood fibers to an ivory-smooth, satin sheen. The exposed wood remains completely raw and unsealed, allowing its natural moisture-regulating properties and intoxicating cypress scent to perfume the home for generations.