Kintsugi is repair with urushi lacquer and precious metal powder. Much of what is sold as a kintsugi kit is something else, and the difference decides whether the bowl can be used.
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Wikipedia defines kintsugi as repairing broken pottery by mending the breaks with urushi lacquer dusted or mixed with powdered gold, silver or platinum. It names the materials: ki urushi, the pure urushiol-based lacquer; bengara urushi, iron-red urushi; mugi urushi, half ki urushi and half wheat flour; and sabi urushi, ki urushi mixed with two kinds of clay. The repaired piece then rests in a furo — a humid box, traditionally a wooden cupboard with bowls of hot water — at 90% humidity for between two days and two weeks while the urushi hardens.
That curing requirement is the useful part, because it is a property no substitute shares. Urushi hardens by oxidation and polymerisation in the presence of moisture, which is why it needs the humid box and the weeks. An adhesive that sets quickly in dry air is curing by a different mechanism entirely — it may make a perfectly good repair, but it is not the material the word describes, and it will not behave like it.
Kintsugi kits on Amazon — both kinds, side by side ↗
There is also a hazard worth knowing before you open a jar. Urushi is urushiol-based, and urushiol is an allergen: in most people it causes an allergic skin rash on contact, urushiol-induced contact dermatitis. It is the same compound that makes poison ivy and poison oak what they are — the lacquer tree is in the same family. Uncured urushi is handled with gloves for that reason.
Kit listings tend to lead with the gold. The two things worth finding instead are the base material — whether the word urushi appears at all, and whether the gold is metal powder or a pigment — and the curing instructions, which give the material away regardless of what the description claims. A kit that ships with a humidity box is telling you something; a kit that promises a repair in an afternoon is telling you something else.
Kintsugi kits on Amazon — both kinds, side by side ↗
That is the shelf and not a kit, deliberately: choosing one would mean taking a position on the food-safety question above, which this site cannot source. What the shelf is good for is the test this page just gave you — the first page of it puts a kit advertising itself as dishwasher safe next to one that says urushi, and the curing instructions tell you which is which. The lacquerware guide below covers what urushi is and what destroys it.
SourcesThe scent exists because the tree was infected. Uninfected wood is pale and light — whatever was added.
There is no dominant standard behind the number. Two #1000 stones can cut differently.
Glass dents, rolls and chips edges rapidly. Wood is self-healing — but grain matters more than "hardwood".
Two of these are the same knife. And a nakiri suits either hand; the usuba it resembles does not.
JIS defines it — and the definition says most washi today is machine-made from chemical pulp.
Carved from a single piece, so a snapped tine is not a repair. The tine count is a spec, not a score.
Not a quality ladder. Natural hair holds powder; synthetic is built for cream and liquid.
ISO and Japanese labelling define how matcha is made. Neither defines a grade.
Ground on one side only. The wrong side does not cut badly — it does not work.
Blue holds an edge longer and is harder to sharpen. Which is better depends on how often you sharpen.
One protects the blade, the other eats it. Scrubbing the wrong one leaves the knife worse off.
Western knives sit at 52–58 and 20–22°; harder steel is what permits 15–18°. Higher is a different bargain.
Repair is subtraction — grind past the chip on a coarse stone, then work back up the grits.
A gifted knife is said to sever the relationship. The custom is that the recipient hands back a coin.
Friction-fitted, not bonded — so it can be replaced. And a D-shaped handle is made for one hand.
The usual fix starts by soaking it. A seiro maker calls soaking strictly forbidden.
Dishwasher, microwave, sunlight. All normal, all irreversible on urushi.
Uncured urushi gives most people a rash. Cured, reactions are possible but less common.
A prefectural institute put eleven lacquer films through JIS Z 2801. Most came back undetectable.
The original ceased production around 1900. Since 1973 the word has meant pattern welding — decoration.
It conducts heat badly. That is the product — and it is also why it cracks.
Unglazed clay is porous until rice starch seals it — one simmer, once.
Induction heats metal, not clay. Most donabe never get warm — and cannot be converted.
Not urushi against epoxy. Whether the material states food-contact compliance.
Pointed where Chinese ones are blunt. And two ordinary gestures read as funeral rites.
Sumi is soot held by animal glue. India ink needs no binder and dries waterproof on its own.
The body is impermeable. It is the decoration that is exposed — and you can feel which kind it is.
One boils water and gives you iron. Putting the other on heat cracks its lining for good.
The spots appear in the first week. The makers’ association says do not take them off.
The form is settled by a 2003 paper. The amount is not settled by anything.
