漆塗りの「青息」と「白息」Urushi-nuri “Blue breath” and “White breath”


I’ve just finished a tense overcoat recently, so I’ll write this story on my blog.


Do you know the words “blue breath and” white breath “?


When it’s cold, it’s said that the breath is white, but it’s a little different. I think it is a word that is often used by Maki-e Artisan and Nushi who paint.

漆塗りの乾かす時の見極め How to determine when the urushi is dried


After applying the urushi, check the temperature and humidity and dry it.


It cures at a temperature of 20 ° C or higher and a humidity of 60% to 80%.


It is the most difficult to control the temperature and humidity. The reason why it is difficult is that it depends on the local climate, the four seasons of nature, and the daily weather. In Japan, urushi dries faster in the summer and slower in the winter.


It’s not just about humidity, it also requires temperature.


During the rainy season, when it rains heavily, the humidity outside becomes 100%, so no matter how much you use a dehumidifier to lower the humidity, it will not go down. A general dehumidifier drops to around 70% to 75% at most, but it seems to be quite difficult to do less than that.


It depends on each craftsman, such as the environment to apply, the thickness to apply, the tools, and the viscosity of the lacquer used. To some extent, it is an individual, and there may be many parts such as experience and intuition.

乾きの確認 Confirmation of dryness


How do you check the dryness of the applied lacquer?


This confirmation work, I do quite carefully. If I neglect to confirm here, I will fail as if Urushi was angry with me. (I have failed many times)


What am I doing after painting? .. .. .. ↓

  1. 漆を塗る
  2. 1〜2時間後くらいに塗ったところに息をかけて確認
  3. 数十分〜数時間毎に再度息をかけて確認
  4. ひたすら時間ごとに確認
  1. Apply lacquer “Urushi”
  2. Check by blowing on the place where I applied it about 1 to 2 hours later.
  3. Check by blowing again every few tens of minutes to several hours
  4. Check every hour


I think that the interval of time to check and how to put it all differ depending on what you applied. All this correct answer is different then and then. In some cases, I may have to stop and wipe it off and reapply it. I don’t know the correct answer until I do it. I think I have no choice but to try a lot and increase the success rate within myself.


If you touch something that has been applied in a non-drying state and it dries as it is, it will fail.


As a way to check without touching, gently blow on the painted object and see the reaction of the lacquer “urushi”.


If the dry reaction progresses when you blow on it, it will become bluish-black in the early stages. I don’t have a photo, but when the oil floats in the muddy water, it looks like a rainbow, and it has a bluish-purple tint.


This bluish feeling is called “blue breath (Aoiki)”.

青息 Blue breath


“Blue breath” → The lacquer moves in a liquid state while it is still curing and is undergoing a curing reaction.


If the state of “blue breath” continues, the lacquer will still move, so if the lacquer keep it in the same state, it will accumulate and cause shrinkage, so I may change the placement.


Also, if this “blue breath” condition is too long, it may dry too slowly, so it may be replaced in a humid place. This decision depends on the weather of the day, the weather after that, and the environment.


As time goes by, the bluish color changes. When it is blown on it, it gradually becomes cloudy and white.

白息 White breath

貝を含む研出蒔絵の上塗りなので少しボコボコしています。(縮みではありません)It’s a little bumpy because it’s a top coat of Togidashi Maki-e including shellfish. (Not shrinkage)


This white cloudiness is called “white breath (Shiro-iki)”.


“White breath” → Hardened considerably, lacquer does not move, solidified


When it seems that it will shrink by the time it reaches this “white breath”, I move the humidity to a lower place. Sometimes it’s too late or it’s in time, and it’s up to the decision at that time.


Even if “white breath” comes, it may shrink depending on the thickness applied and the environment in which it is placed. Also, if the humidity and temperature are high, such as in the summer, I may get a white breath in about 2 hours, and if I apply a thick coat, it is very likely that it will shrink afterwards.


Basically, this “white breath” is said to be in a hardened state.


In my case, I’m quite worried, so even if I can confirm “white breath”, I will check it again every tens of minutes for a while. I check until I get the perfect “white breath”. Even after I can confirm it, I can’t sleep on the night of the day I applied it, so I’ll check it again.


With that much care, lacquering will most likely succeed as if it were rewarded. It really looks like a living thing, and if you don’t handle it carefully, the beautiful coating will disappear. If I fail, shrinkage will appear.


If I neglect to check even a little or leave it unattended, it will fail in my case.


Also, after applying “white breath”, let it harden more firmly for 5 to 7 days. Obviously, the finish will not be beautiful unless it dries properly. This drying is really difficult, but the joy when it’s finished is also great.


I think that this two-step hardening mechanism of “blue breath” → “white breath” is chemically occurring. (It’s just my personal understanding) There is no literature that explains or proves that “blue breath” is an enzymatic oxidative polymerization and “white breath” is a state of automatic oxidation. However, I personally recognize that adjusting the temperature and humidity at the stage of changing from blue breath to white breath is very important for keeping the coating film clean.


The curing mechanism of lacquer has been covered in past posts, so please read it if you are interested.


With this kind of feeling, it is a work that requires experience and skills so far in one painting process called lacquering, so I think that there was one category of painters “Nushi” in the division of labor. This one work process is very deep.

蒔絵の青息 Makie’s blue breath


By the way, the timing of sowing the powder of Makie is also “blue breath”.


For lacquer “urushi”, slowly wait for a breath in low humidity.


In the case of Maki-e, after drawing, put it in a humid Muro (wet Muro) for 15 to 30 minutes. Then, when the blue breath comes, sprinkle the powder. If you pass this blue breath and become white breath, it will be too dry and the powder will not enter the urushi.


The dryness of lacquer varies from day to day, so observe the speed at which it dries.


In my case, I use Keshi-powder and Hiragoku-powder that are not polished or sharpened too much. For large Maru-fun or Hirame-fun, I sprinkle immediately. Instead, I sprinkle more often.


※The method depends on the individual.


I think that only the person who did this hardship can understand it. I hope that the hardships of facing lacquer over time as a lacquer maker will be conveyed.


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