Types and Characteristics of Finishing Coatings

There are various methods of finishing (coating). Each finishing method has its own strengths and weaknesses, and development continues to improve upon these. Even with something as common as polyurethane resin, it's difficult to make general statements. Additionally, different coatings may be used for filling the pores (such as wood vessels), further complicating the process.

The wooden items we carry are finished with methods carefully considered and selected by trusted artisans known to the shop owner. The shop owner has verified these methods, and we do not handle products from artisans who choose finishes that are not recommended. Since there are an extremely wide range of finishing methods, especially when considering combinations, we will introduce the representative finishing coatings here. (However, please note that various innovations have been made to overcome the shortcomings of each coating, so please read this as a general reference.)

oil

This is a coating method in which primarily plant-based oils are absorbed into the wood. Since it creates almost no film on the surface, you can feel the natural texture of the wood. On the other hand, oils tend to be easily absorbed through regular use, so the coating effect does not last long. When applied with oil alone, the wood darkens to a deeper color when the oil soaks in, and as the oil fades, the color in those areas becomes lighter.

For example, if you drink hot coffee from a cup that is simply oil-finished, you may be bothered by the substances that come out of the cup if you want to enjoy the delicate aroma and flavor of the coffee itself. The degree of this varies depending on the type, freshness, and amount of oil (especially the oil used in maintenance). Also, the wood itself contains substances that affect the taste and aroma, so it varies depending on the species of tree and the degree of dryness, and the smell of the previous drink will remain. The extent to which you feel this varies from person to person.

This is the simplest finishing method, and it is easy to maintain. Since there is no coating, scratches are not an issue. You can enjoy the aging process. This is the finishing method most preferred by the shop owner.

Urethane Resin

A coating is made on the surface with urethane resin and then hardened. Applying it thickly will give it a glossy finish, but it will also remove the texture and scent of wood. This can be an advantage or disadvantage depending on your preference.

The raw materials for urethane resin paint (before it hardens) contain substances that are harmful to the human body. For this reason, some people may have a negative impression of urethane. However, once the urethane has bonded (hardened through painting), it will not break down again under normal use, and the urethane resin used in the tableware we sell complies with Japan's Food Sanitation Law. Additionally, even when the final finish is made with oil or glass coating, urethane resin may be used for sealing the wood and reinforcing it before the final layer is applied.

The urethane resin will completely harden and form a coating, so it will have little effect on the taste and scent of the wood. You may notice a paint smell when you first start using it, but the smell will decrease as you use it.

We recommend that you contact the manufacturer or a professional to restore areas where the paint has peeled off. For products purchased from our store, please feel free to consult with us.

Glass Paint/Coating

This is a relatively recently developed painting method. It creates a thin coating that protects the wood, but the paint has high permeability into the wood and does not damage the texture of the wood.

For example, if you want to enjoy the delicate taste and aroma of coffee, oil finishes have the disadvantages mentioned earlier. However, glass coatings completely harden and form a layer, so their effect on taste and aroma is minimal. You may notice a paint smell when you first use it, but it will diminish over time. However, if the coating is thin, the scent of the wood or the previous drink may linger. These factors all depend on the type of paint, the coating method (thickness of the coating), and the type of wood.

To restore the peeled-off paint, you will need to repaint with the same glass coating. However, since the coating is thin, replacing it with oil will not be very noticeable. Maintenance can be done in the same way as with an oil finish. If you wish to restore the peeled-off paint with glass coating, we recommend that you contact the manufacturer or a professional. Please feel free to consult with us regarding the products we sell.

Urushi

Urushi is a traditional coating that has been used for a long time, and it is renowned for its strength as an adhesive as well. It is even used in Kintsugi (the art of repairing broken pottery with gold).

In general, wooden items can easily experience deterioration of the coating or changes in the wood, such as discoloration, when exposed to acidic or strongly alkaline substances. However, urushi is extremely resistant to these conditions. The strength increases with additional layers, and it also develops a glossy finish. While most urushi finishes are thick coatings, even with regular finishes, the permeability to gases and liquids is never zero. Therefore, depending on the type of wood and its dryness, the scent of the wood may still pass through.

To restore areas where the coating has peeled off, we recommend that you ask the manufacturer or a professional. Please consult with us regarding the products we sell.

Unfinished (No Coating)

Here is the final finishing method: leaving it uncoated. In this case, it is often finished with a blade without using sandpaper.

When the surface of the wood is cut with a sharp blade, it repels moisture to a great extent. For example, a surface finished with sandpaper will absorb water, whereas a surface finished with a planer will repel water. Sanding can be considered a process to allow finishing paints to penetrate.

By finishing the wood with a blade, it becomes somewhat resistant to stains and dirt even without any protective coating. However, it remains vulnerable to discoloration caused by chemical reactions. The durability depends on the wood species, the part of the wood, and the grain pattern.