GOENNE | What is Urushi? | Japanese lacquer and Kintsugi Supplies

Urushi is very precious to the Japanese. Antiquity discovered in Japan dated to over 9000 years ago. Japanese' use and application technique of this tree sap has reached its height that none other countries could match.

URUSHI Japanese Lacquer

The Gift from Nature

20th century industrialization and technological advancement has brought us abundant new materials. Most of which are synthetically engineered in lab and mass-produced in factories, using artificial material and chemicals. 21st century is the era when we started to see the impact that modernization has brought: pollution, mass depletion of resources, climate change, toxic-intake by human and animal etc...

Revisiting the ancient intelligence of Urushi lacquer cultivation and usage, we realized there is a lot this magical material has been providing. It is no doubt THE gift from mother nature.

What is Urushi?

urushi lacquer, Japan urushi, traditional kintsugi, Japan-grown urushi

Urushi (Japanese lacquer) is a natural tree sap from the urushi tree. Before the age of Super-Glue and epoxy, people has been using this organic material as a strong adhesive and coating material. When in its raw state, urushi lacquer is toxic to touch, the natural enzyme causes allergic reaction on the skin for most people. Howvever, after natural polymerization process, this material stabilizes and becomes water-repellant and extremely durable with anti-bacterial and deodorizing properties. The longer a lacquerware has been used, the more rich the luster finish would become.

100% all-natural. It is a magical gift from nature.

Uses of Japanese Lacquer

In Japan, lacquer is commonly used as adhesive and finish material for utensils, furnitures and architectural works. Doctrines from as early as 14th century, recorded urushi lacquer as herbal medicine for both internal and external use. In rural towns of Japan where urushi are cultivated, the plant is also served as local delicacy. Ask the urushi foresters and they would recommend "urushi tempura"! Japan is world-renowned for its lacquerware. All families use lacquerware for food serving, and it is common for schools, restaurants and hospitals to serve meals in lacquerware due to its hygienic properties and durability.

Properties of Japanese Lacquer

When in its raw state, urushi tree sap is volatile. The enzyme actively oxidates and ferments.

It's main ingredient URUSHIOL (also found in poison oak) is known to give people allergic reaction if in contact with skin. However, after natural polymerization (hardening), it stabilizes to become a solid and extremely durable material.

The ideal condition for polymerization is 25-30˚C at 70-80% humidity. High humidity speeds up the "hardening" of liquid lacquer. So "drying" is not the right concept when applying lacquer. For centuries, Japanese urushi refiners have perfected their skills in calibrating the urushiol-to-water ratio and manipulating the enzymes too create a wide variety of raw urushi products suitable for different applications.

Japanese' mastery in urushi (from cultivating, tapping technique, refining methods to artisanal applications) have gained world-wide recognition to be of top quality.

Durability

Completely cured lacquer surface becomes water-repellent. It also resists acids, alkali, alcohol. It remains unaffected by highly corrosive substance. It is like the ancient-version of powder-coating but without the chemicals.

Anti-bacterial

Scientific studies has been conducted in Japan and found that urushi-lacquered surface deters the growth of some major food-poisoning bacteria and one type of virus (salmonella, MRSA, E-coli, and SARS-coV-2).* As a result, urushi-lacquered food-serving wares such as bowls, bento boxes and chopsticks remains popular in Japan.

FOOD-SAFE? FOOD-GRADE?

Food-safe and Food-Grade standards from North America and EU countries are set up to test and qualify artificial and chemical materials for food-contact use (e.g. plastic, stainless steel, epoxy, chemical coating etc..). Japanese Urushi lacquer, uniquely as an all-natural material, has not been examined under such standards. However, it has been used as a finish material for dining ware and serving utensils for many thousands of years in Japan.

*Reference: Lab Report from Urushi Revitalization Association (test conducted by JNLA, Japan National Laboratory Accreditation system)

Natural Deodorization

As urushi deters bacterial growth, it also act as a deodorant. In recent years, companies in Japan has been incorporating urushi into products such as fabric, socks and in-soles.

Luster & Finishes

As a hardwearing material, urushi can take chiseling, sanding and polishing. Japanese lacquer craftsmen have perfected their techniques in creating a wide variety of delicate texture and decorative finishes for lacquerware. Through the hands of Japanese artisans, its unique beauty represents Japanese aesthetics like no other material does. This longer a well-crafted lacquer bowl is used, the more beautiful the surface becomes.

Urushi Rash & Allergy

Last but not least, it is important to learn how to handle urushi lacquer properly to avoid direct skin contact.. The urushiol content in urushi is what makes it durable, glossy and "food-safe". However, it is also the same content (when in wet state) that gives most people bad skin allergy like poison ivy. Once this element comes in contact with your skin and enters your body, it travels, so it doesn't mean only the area that comes in contact will have allergic reaction. The rash could appear anywhere, usually outer and inner elbow, palm, thighs etc... And touching or scratching it will make it spread. There is only temporary relief of swollen redness, itchiness, blistering until urushiol is completely out of your system, which could be 1-2 weeks.

Even artisans who handles urushi everyday, including urushi cultivators have to prevent skin contact as much as possible, as there is no immunity. Everyone has their own "remedy", hydro-cortisone cream would typically be recommended by pharmacists but usually does little to relieve. My personal best remedy is to run the skin under cold water, or put ice pack over infected area for quick and immediate relieve, the swellness and ichiness immediately subside until it flairs up again in the next episode.

Wear protective covering gear all the time while working with raw / wet urushi. Coat your arm and plam with a layer of lotion before working would also help to prevent quick absorption of urushi onto skin. In case you notice urushi touches your skin, wipe it quickly with oil. (soap and water won't do it). Follow by alcohol.

Note that completely cured (polymerized, hardened) urushi becomes very stable and non-toxic. It is when its in wet and raw state that you have too be extrememly cautious while handling.