What Is "Shin-Urushi" in Simplified Kintsugi? Differences from Real Urushi and Safety Considerations

If you've accidentally broken a dish and started searching for an easy way to repair it, there's a good chance you've come across "shin-urushi" — a material commonly used in simplified kintsugi.

"It doesn't cause skin reactions, right?" "It's easier to use than real urushi?" — These kinds of misconceptions are surprisingly widespread when it comes to shin-urushi.

In this article, we'll cover what shin-urushi is, why it can no longer be used on tableware, and what you should use instead if you want to repair dishes with kintsugi — from the perspective of a kintsugi practitioner.

What Is Shin-Urushi?

Shin-urushi is a brand name by "Fugu-Jirushi" (originally a coating for fishing rods)

"Shin-urushi" refers to a product called "Fugu-Jirushi Shin Urushi," sold by Sakurai Fishing Tackle Co., Ltd.

It was originally developed as a coating for fishing rods, and is known for its lacquer-like gloss and texture while being easy to apply. For a time, it became widely used as a finishing material in simplified kintsugi.

Many people assume from the name that it's a "newer version of urushi" or a "hypoallergenic natural lacquer," but shin-urushi is an entirely different material from real urushi (lacquer).

While urushi is a natural resin harvested from the urushi tree (Toxicodendron vernicifluum), shin-urushi is a synthetic coating made primarily from cashew nut shells.

The Key Difference Between "Urushi" and "Shin-Urushi" in Kintsugi

To fully understand the role of shin-urushi, it helps to know the structural difference between traditional kintsugi and simplified kintsugi.

	Traditional Kintsugi	Simplified Kintsugi
Adhesive	Raw urushi (natural resin from the urushi tree)	Synthetic adhesives such as epoxy resin
Gold finish	Dusting with gold powder	Coating with shin-urushi (gold-colored paint)
Safety for tableware	Safe for food use	Risk of harmful substances leaching out

Traditional kintsugi: bonded with raw urushi, finished with gold powder

In traditional kintsugi, broken pieces are bonded with raw urushi (or mugi-urushi, a wheat-starch and urushi mixture). The joint is then reinforced with additional coats of urushi, and finally finished by dusting with gold powder.

Because only natural materials are used throughout the process, the repaired piece is safe to continue using as tableware. While it requires more time and effort, the greatest advantage is that the repaired dish can go right back into everyday use.

Simplified kintsugi: bonded with synthetic adhesive, finished with shin-urushi or similar

In simplified kintsugi, synthetic adhesives such as epoxy resin are used in place of raw urushi. The gold finish is then achieved by applying shin-urushi (a gold-colored paint).

In other words, shin-urushi is not a "urushi made specifically for simplified kintsugi" — it is "a gold-colored paint that has been used as a substitute for gold powder."

Raw urushi is used for "bonding"; shin-urushi is used for "coating"

To put it simply:

• In simplified kintsugi, "coating with shin-urushi" replaces the "gold powder dusting" used in traditional kintsugi.
  

• The role of "urushi as an adhesive" in simplified kintsugi is filled by synthetic adhesives.

The widespread misconception that shin-urushi is a substitute for urushi likely stems from the confusing product name itself. With "urushi" in the name, it's understandable that people assume it belongs to the same family.

As a coating material, shin-urushi may serve as an alternative to urushi — but in the context of kintsugi, the story is quite different.

Shin-Urushi Can No Longer Be Used on Tableware Following Japan's Food Sanitation Act Amendment in June 2025

As a result of the Food Sanitation Act amendment in June 2025, shin-urushi can no longer be used on food-contact utensils or containers.

The amendment changed the regulatory framework from a negative list system (specifying what is prohibited) to a positive list system (specifying only what is permitted).

With tightened safety standards, shin-urushi and other synthetic lacquer-type materials were deemed non-compliant and banned from use on tableware.

▲ Shin-urushi was still on the shelves of a kintsugi supply section at one store

The Hidden Risks of Simplified Kintsugi Kits for Tableware Repair

Since the law was amended, some simplified kintsugi kits have started marketing themselves as "compliant with the Food Sanitation Act." However, this requires careful attention.

Compliance only applies to the adhesive component

Even when a product is labeled as Food Sanitation Act compliant, in most cases this refers only to the synthetic resin components — such as the adhesive, putty, or bonding liquid.

A compliant adhesive alone does not make a piece "safe for tableware use." What matters most is what material is used for the surface finish — the part that comes into direct contact with the mouth.

The food safety of brass powder requires attention

Brass powder — commonly used as a finishing material in simplified kintsugi kits — is an alloy of copper and zinc. While it has an attractive gold-like appearance, unlike gold or silver, its food safety has not been verified.

Japan's Food Sanitation Act limits the lead content in metals used on food-contact surfaces to 0.1% or less. Lead is toxic to the central nervous system and kidneys, and regulations are being tightened not only in Japan but worldwide.

The Hohken Quality Evaluation Institute, which conducts impartial quality testing, lists lead content in brass as one of the non-compliance examples in its database.

Is it safe because the metal is encased in resin?

Many simplified kintsugi kits released after the Food Sanitation Act amendment achieve a gold appearance by mixing metallic powder into synthetic resin.

While the metal powder is enclosed within the resin, I do not believe this means it is completely absent from the surface.

Polishing the surface to bring out its shine increases the likelihood of exposure, and the risk of zinc leaching when in contact with acidic foods cannot be entirely ruled out.

ANYTSUGUI's Position

Using brass powder in kintsugi is perfectly fine for items that do not come into contact with the mouth, such as vases or decorative pieces. However, we do not recommend using brass powder for repairing tableware or items that touch the mouth, due to food safety concerns.

The often-overlooked issue of epoxy resin allergies

There is another issue that often goes unnoticed. Epoxy resin — commonly used as an adhesive in simplified kintsugi — is also a known allergen that can cause contact dermatitis.

Despite this, many simplified kintsugi kits prominently advertise that they are "less likely to cause skin reactions than real urushi," while making no mention of the allergy risk associated with epoxy adhesives.

How to Safely Repair Tableware with Kintsugi

Only gold, silver, and platinum powders have verified food safety

Currently, the only metallic powders with tested and verified food safety are gold powder, silver powder, and platinum powder.

Metal Powder	Food Safety	Characteristics
Gold powder	Verified	Resistant to discoloration over time. Higher cost.
Silver powder	Verified	More affordable, but prone to tarnishing over time.
Platinum powder	Verified	Distinctive luster. Higher cost.
Brass powder	Not tested	Not verified for use on tableware.
Copper powder / Tin powder	Not tested	Traditional usage exists, but no formal testing conducted.

For repairing tableware, always choose gold, silver, or platinum powder.

Traditional kintsugi using raw urushi is the safest option for tableware

When it comes to the adhesive as well, traditional kintsugi using raw urushi is the safest choice for tableware.

Raw urushi has been proven safe for food contact after full curing throughout Japan's long history. While some synthetic adhesives carry "Food Sanitation Act compliant" certification, most lack sufficient long-term safety data.

ANYTSUGUI kits let you finish safely with real urushi and gold or silver powder

ANYTSUGUI kintsugi kits are traditional repair sets that use natural raw urushi with gold or silver powder. Dishes repaired with these kits can continue to be used safely as tableware.

We believe that when you repair a dish, it's because you want to use it again. That's why ANYTSUGUI creates kits using real urushi — so that every repaired piece can go right back to the table.

Even if traditional kintsugi sounds intimidating, our kits include detailed step-by-step instructions and video guides, making them accessible for complete beginners. While the process involves more steps than simplified kintsugi, the greatest value is being able to safely return the repaired dish to your everyday table.