At Hitotsuya（ひとつ屋）, we do more than use commercially prepared dyes. We also experiment with making our own dyes and pigments from plants grown in our fields and from the soil around us.
At the time of this record, we were working with Japanese indigo (Persicaria tinctoria, known in Japan as tade-ai) and with earth collected from the field.
Making dye from field-grown Japanese indigo
We first made an indigo colourant from Japanese indigo grown and harvested in our own field.
The leaves are soaked in water and allowed to ferment. After the leaves are removed, slaked lime is added and the liquid is stirred vigorously to incorporate air. The blue pigment gradually forms, settles at the bottom of the container and separates from the water.
The detailed process is introduced in our Japanese-language article, How to make precipitated indigo, indigo paste and dried indigo cakes.
This method has also been examined academically. A presentation abstract published by the Japan Society of Home Economics, Production of precipitated indigo and examination of dyeing conditions using Polygonum tinctorium, compares soaking times, stirring conditions and dyeing results with different fibres.
After the upper water is poured away and more moisture is removed, the pigment becomes a thick paste. At Hitotsuya, we call this doro-ai, literally “mud indigo”.
When the paste is dried further into a solid form, it becomes aijō, a dried indigo cake or tablet.
▼ Indigo paste after part of the water has been removed
Making a pigment from field soil
Our other experiment was to make a pigment for earth dyeing from soil collected in the field.
We wanted to see what colours familiar local earth might reveal on cloth. Unlike colour extracted from dye plants, soil has its own mineral character, so we tested ways of using that natural colour as a pigment.
▼ Preparing a natural pigment from field soil
Working towards the colour we want
We had already tested both the indigo paste and the soil pigment on cloth. At this stage, however, neither produced the colour we were hoping for.
Results with homemade dyes and pigments change with the condition of the material, the preparation method, the cloth and the dyeing conditions. Rather than presenting an unfinished experiment as a completed technique, we continue to observe the colours and adjust the process.
A later dyeing test using the indigo paste is recorded in our Japanese-language article, Dyeing with precipitated indigo using a hydrosulphite vat.
Growing plants, gathering soil and making colour with our own hands are all part of the same process. Reaching the colour we want may take time, but we will continue testing and recording what we learn.