There are two kinds of white pigments known as the original pigments of ukiyoe in the edo. White lead （enpaku 鉛白)and gofun （胡粉grinded shell). This time, I introduce the making method of the former one.
White lead has been made from ancient times. It was already made in Roma antiqua . The method of making can be simply explained as follows. “Pour fruit vinegar to a pot and put lead over that.Then stack the pots in manure and leave during about 6weeks.“This method is called “Dutc Process"in the precent. It’s said white lead was derived from China.Although there is the document described that one priest made himself a specimen of white lead and presented it to the majesty in 692 A.D. , but the practice manufacture was commenced in the first of 17th century in this country . I have not yet found a confirmatory document described how white lead had been made in the edo period .But It’s written in ｢On Japanese Pigments 」by T.Takamatsu published in 1878 , that “it is highly probable that the present（1878) method of making was derived from China,in as much as it resembless in it’s main features the process that is carried out in that country, where it’s said to have been made more than 2000years ago.And in addition this,the almost same method is described in "tenkou-kaibutsu"that is a science technical book published in 1637 in China. Considering these facts, the method done in the edo period must be that. The method is as follows,"put a grating of bamboo on a earthen dish poured vinegar and put lead on the grating . Caver the all by a barrel shaped vessel and heat the dish from under by charcoal fire.” ｢The Making Method of Pigments 」written by Michiya Yano in1904 , describes that the method done in japan is basically the dutch process. The chemical change in above two method is same.The change of metallic lead in the vessel is as follows, 1 lead ＋humidity＋oxygen → lead hydroxide 2lead hydroxide＋acetic acid→lead acetate 3lead hydroxide ＋lead acetate→lead subacetate 4lead subacetate＋carbonic acid gas→basic lead carbonate（white lead ) The efficient temperature for this chemical reaction is 40℃～50℃.And the reason of the use of heat source must be for the maintenance of this temperature and to make it efficiently better . In the dutch process,carbonic acid gas is provided by fermentation of manure.And in the other process,it’s by charcoal fire.But reading the documents, the both vessels are the constructions shut off by partitions from the supply source（manure and charcoal fire ) . So I could see that a little amount of carbonic acid gas leaking out through very small cracks is enough to the chemical change.（Humidity, oxygen and acetic acid on the formulas are matters in a spontaneous manner and automatic.)
Therefore, I did the way as follows,
1Put a roll of white lead on sticks over an earthenware cup poured vinegar. Put this and a piece of charcoal into an earthen ware pot that could be shut tightly. White lead is better in roll shaped than tabular.
2I heated the pot to make the inner 40℃～50℃ in a few times in a day.But I thought on the way that if I put it at sunny place, the temperature of that became so since now was summer.After I noticed it, I left it outside where was well sunlit.
3This photo is the state after 6weeks.（Vinegar must be added on the way if the residual amount itself becomes a little. )
4Brush the white lead on the surfaces by a hard brush or bending over again.
5After grind it well, add water and stir.
6Filter the milky liquid through a sieve .There is decent lead that has'nt changed yet.
7Pour the filtered liquid to paper filter on a funnel. Dry and finish.
8 The remained lead unchanged is put back into the pot and put a lid .Then leave it at the place and wait for weeks again. The velocity of chemical reaction depends much on the quality of lead itself or environmental condition.
Reading as above, perhaps you wonder “why is water added after grinding？It’s no problem to filter the powder through a sieve without water, isn’t it ？ ” The reason why water is added is to wash away lead acetate that is the intermediate and water soluble to make white lead more pure.（White lead itself is insoluble.) And it’s also useful to separate pieces of lead which haven’t became white lead yet since those tend to settle on the bottom of a mortar , being added water. White lead is venomous.If you make it by yourself, take care not to touch by the hands directly and absorb.
“On Japanese Pigment ” as above says that the milky liquid after passing through a sieve is then stired and its supernatant liquid is collected to separate finner particle. The finest one is used for ingredient of cosmetic or porcelain ennamels.The particles after the second class are used for pigment and so on. But since my purpose of use is for pigment and I didn’t want waste the particle , I didn’t do that separating work by collecting the supernatant liquid.
There have been many methods to make white lead.（German process, French process and Electiochamical process, etc.) But I leave out them here since they are unrelated with the method done in the edo period in Japan. I think the domestic white lead today can’t be the dutch process. Anyway ,I think the use of titanium white as white pigment is general in printers today.
The white lead I ’ve made this time will be used in the next kuniyoshi reproduction. It tends to turn black by time passing.So we can see the use due to that. Look at the part of wave splash on the photo ！
After that, I made a simple manufacturing device of making white lead, refering to old literatures.
