Nunokise — cloth reinforcement

Choose the fabric before you begin, because its stiffness, thread density, and drying behaviour determine every downstream decision. For small items with pronounced curves, a fine linen gauze (kanreisha) or a 55 % cotton / 45 % linen blend wraps tightly, cuts cleanly, and dries flat without deformation. For large kanshitsu (dry-lacquer) pieces, dense ramie under-cloth provides the structural rigidity the build demands, though its uneven thread thickness can leave a surface that is visibly textured to the naked eye. A thicker cotton under-cloth works for overall texture on medium pieces but absorbs more lacquer and needs an extra one or two days to dry. Avoid 100 % linen: the warp and weft stretch at the intersections during application, the fabric curls after drying, and it tears when cut. If you are working with a very thin silk or paper, note that it will need a deep-lacquer base coat before it will adhere properly.

When it is rightThe chosen cloth lies flat on a test surface without curling, cuts with a clean edge, and its thread pattern is regular enough that, once scraped, the surface reads as a uniform plane rather than a bumpy weave.

When it goes wrongA cloth that is too soft will deform under the spatula, trap air bubbles, and curl at the edges after curing. Recovery: discard the piece and switch to a stiffer fabric; do not try to flatten a deformed cloth with more lacquer, as the distortion is structural.

Weigh 10 g of glutinous rice flour on a digital scale and add four parts water by volume. Stir the cold mixture continuously until every granule is dispersed and no dough clumps remain; any lumps left at this stage will become hard spots in the finished adhesive. Place the pot on a stove at low heat and warm slowly, stirring without pause. As the temperature rises the liquid will thicken and turn a translucent gel; keep stirring until the whole mass is uniformly gel-like. Remove from the heat but continue stirring to prevent the residual heat from scorching the paste to the pot. Cool the paste naturally or by setting the pot in a bowl of cold water while stirring. Once cool, cut the paste into portions, wrap in plastic, and refrigerate. Before use, let it return to room temperature. Mix the cooled paste with urushi at a ratio of roughly one part paste to one part lacquer by volume. Some artisans prefer a heavier paste ratio of 10 parts paste to 7 or 8 parts lacquer, which increases shrinkage and extends drying time. For very thin fabrics such as silk, raw ki-urushi alone may be used without any paste. The finished adhesive should be thick, sticky, and workable—able to coat the cloth evenly without running.

When it is rightA smooth, slightly translucent, uniformly sticky paste that spreads evenly with the spatula and does not separate or run. The lacquer-and-paste mixture should hold a soft ridge when lifted with the hera.

When it goes wrongUndissolved flour granules create hard lumps that show through the cloth as bumps. Burning the paste to the pot leaves a bitter, brittle residue that will not bond. Recovery for lumps: re-stir the cold mixture through a fine sieve before adding lacquer. Recovery for burnt paste: discard and re-cook; do not attempt to salvage scorched paste.

Lay the cloth flat on a clean, hard surface and measure the area of the vessel that needs reinforcement, adding a small margin so the cloth extends slightly beyond the edge you intend to cover. Cut with a sharp knife held at a steady angle, or with scissors if the fabric cooperates. Cutting behaviour depends on the material: kanreisha and the cotton-linen blend cut cleanly in a single pass; the cotton-linen blend requires you to hold one end taut while cutting the rest to prevent the blade from dragging the fabric. Ramie cuts easily once dry but is harder to cut while damp. If the cloth frays at the cut edge, trim the frayed threads back with the knife before proceeding. The cut piece should be a clean rectangle or shape that matches the vessel profile, with no jagged or torn edges.

When it is rightA cleanly cut piece of cloth with straight edges, no frayed threads, and a size that covers the target area with a small overhang for trimming after curing.

When it goes wrongTorn or ragged edges will create a raised, uneven border after curing that is difficult to sand flat. Recovery: trim the damaged edge back with the knife until the cut is clean, or re-cut the piece if the damage is extensive.

Using the hera, spread a thin, even coat of nori-urushi over the area of the wooden substrate that the cloth will cover. Work the adhesive into the grain and into any corners or edges with the tip of the spatula, ensuring no bare wood is left exposed. Lay the cut cloth onto the wet adhesive, starting from one edge and laying it down progressively so that air is pushed out ahead of the cloth rather than trapped beneath it. Immediately press the cloth into the surface with the flat of the hera, working from the centre outward and from the starting edge toward the far edge. Apply firm, even pressure; the goal is to force the cloth into intimate contact with the wood and to squeeze out every air bubble. Corners and curved transitions are the most difficult areas: work the spatula tip into the corner at a low angle, pressing the cloth into the fold. If a wrinkle or bubble appears, lift the cloth at that spot, smooth it out, and re-press. Do not leave a wrinkle to 'set'—once the adhesive begins to tack, the wrinkle is permanent. Check the entire surface for trapped air by running the flat of the hera lightly over the cloth; any soft spot indicates a void that must be re-pressed.

When it is rightThe cloth lies perfectly flat against the wood with no visible wrinkles, bubbles, or gaps. The thread pattern is visible but uniform, and the edges are pressed firmly with no lifting. The surface feels smooth and solid under the spatula, with no spongy or hollow areas.

When it goes wrongTrapped air bubbles create soft, hollow spots that will show as dimples after curing and will delaminate under the weight of subsequent coats. Wrinkles at corners create ridges that no amount of sanding will fully remove. Recovery: lift the affected area while the adhesive is still wet, smooth the cloth, and re-press. If the adhesive has already tacked, the area must be peeled back, re-coated, and re-pressed—there is no in-place fix for a set wrinkle.

Remove the vessel from the furo and inspect the edges. Trim any overhanging cloth or cured adhesive with a sharp knife, cutting close to the vessel's edge but not into the wood. For stubborn cured bits that the knife cannot reach, the HwihoCraft workshop notes that a brief application of heat can soften the lacquer enough to scrape it away. Once the excess is trimmed, take two sheets of fine sandpaper and lightly sand the surface of the cloth. The sanding must be light: the goal is to remove the high spots of cured adhesive and to level the cloth surface, not to cut through the cloth or into the wood. Work in the direction of the grain where possible, using short, controlled strokes. Check the surface by running your fingertip across it; it should feel smooth and even, with the thread pattern visible but not raised. If the cloth is still slightly proud of the wood at the edges, a second light pass with the sandpaper will bring it level. Do not over-sand: once the cloth is flush, stop, because the next step (the sabi ground) will fill the remaining thread gaps.

When it is rightA smooth, even surface with no protruding cloth, no rough edges, and no visible step between the cloth area and the surrounding wood. The thread pattern is visible but lies flat. The surface is ready to accept the sabi ground without any high spots that would telegraph through the finish.

When it goes wrongOver-sanding cuts through the cloth and exposes bare wood, which will absorb the next coat unevenly and create a weak spot. Under-sanding leaves a rough, bumpy surface that the sabi ground will not fully mask, resulting in a textured finish where a smooth one is intended. Recovery for over-sanding: fill the exposed area with a thin coat of nori-urushi and re-press a small patch of cloth. Recovery for under-sanding: a second light sanding pass before applying the ground.

Mix fine clay powder (tonoko) with lacquer to create the sabi ground. The consistency should be thick enough to hold on the surface without running, but workable enough to be scraped into the gaps between the cloth threads. Using the hera, scrape the sabi firmly into the surface, working the mixture into every gap between the warp and weft threads. The thickness is critical: if the coat is too thin, the cloth threads will show through and the surface will remain textured; if it is too thick, the layer will crack as it cures. The HwihoCraft workshop describes the target as an 'appropriate' thickness that fills the gaps without excess. After the first coat has cured in the furo, sand it lightly and apply a second coat. This process is iterative: the HwihoCraft workshop notes that multiple coats are often required to achieve a smooth, even surface, and that each coat must be sanded before the next is applied. The physical effort is significant, especially on larger vessels, and the repetitive scrape-cure-sand cycle is the defining labour of this stage. Continue until the surface is uniformly smooth, with no visible thread pattern and no cracks.

When it is rightA smooth, even ground layer that completely covers the cloth and fills all thread gaps. The surface is uniform in thickness, free of cracks, and ready to receive the subsequent naka-nuri (middle coats) of lacquer. The cloth is no longer visible; it has become an invisible structural layer beneath the ground.

When it goes wrongCracking from excessive thickness: the cracks will propagate through subsequent coats and cannot be repaired by polishing. Recovery: sand the cracked area back to a sound surface and re-apply a thinner coat. Visible cloth threads from insufficient thickness: the surface will feel bumpy and the thread pattern will show through the finish. Recovery: apply an additional thin coat of sabi, cure, and sand.