Commercial paper and cloth sold for art materials include those that have a bleeding processing and unprocessed raw.

To prevent it from bleeding when the coloring material is placed, the basal material such as Japanese paper, silk, tree, etc. are applied. The solution used at that time is called a size agent, and the processing is called sizing. In Japan, it is called dosa (alum water), which is the main component of glue, and its processing is called dosa pull.

Dosa does not mean that the same effect can be obtained to all base materials by manufacturing and applying in a certain way. The glue produced by boiling and purified animal bones and skins has individual differences due to the unique status change and natural material, and it requires knowledge and understanding of the material in the work.

In modern times, paper with bleeding is also sold, but there are many unprocessed products, and most of the silk, azabu, and wooden plates are forced to do self -processing. Dosa pulling is a must -have process, depending on the work that performs the dressing and backing. In the backing, the work is drained by brush and spraying, so it also affects the work, such as the effect of the effect.

It takes time to do all the processes from creating a dosa solution to pulling it to the base material, but there are also benefits.

It is a great advantage not only to increase the options of basal materials by doing it yourself, but also to expand the range of gradation and blending that takes into account the characteristics of each color, base material, and expression technique.

However, due to the nature of the base material (Japanese paper and silk) and the nature of the glue, which are susceptible to high temperature and moisture, Dosa may be worse depending on the environment and the combination with Dosa. It is also possible to control by adjusting the concentration and number of applications of the aqueous solution, but for this, not only knowledge and experience of color materials and color materials, but also data collection is indispensable.

Pigment TOKYO creates and verifies a sample that compares the difference between Dosa's collagenia and base material, and introduces a part of it.

The material was verified using the original glue of Pigment Tokyo.

In general, when making dosa, alum is added to enhancing the effect of solidifying the glue film, but high jelly strength hardens the film without any alum.

This glue is recommended to use 3 to 4 % for Japanese paper and about 1.5-2 % for silk, but as described above, the sizing effect varies depending on the temperature and humidity. Please adjust the concentration and the number of applications depending on the situation and preference.

There are two types: solid type sheen and pork solution created at a 20%concentration.

It takes a long time to make a dosa, but it has good preservation and can be stored for a long time at room temperature. It is recommended if you make a lot because it has excellent cost performance. Mold may occur in a hot and humid environment, so please store it with a desiccant.

20 % pork solution can be used just by diluting, so if you want to try this product, or use a small amount, it is a highly convenient product. In addition, preservatives are added, and it can be used for about a year for refrigerator storage.

It will solidify at low temperatures.

Please refer to the special article below for the details of the product and the plategen water solution made from the plategen.

Gluegen / physical properties
・ Vehicle: Approximately 11 mpa ・ S
・ Jelly strength: JS 610 ~ 630 g
・ Payha: PH 5.0 ~ 6.0
 
Base material
・ Kozo paper (5 momme, 10 momme, 15 momme, 20 momme)
・ White hemp paper
・ Picture silk (2 -丁 ghoul special, 3 丁 gutter)

◾ mulberry paper

Verification environment: September 2, 2022 Room temperature 22.7 degrees Humidity 60%

[Use material]

Color materials: Summonor / Shinwa paint Urushi 9, Upoi 13 / Watercolor paint / acrylic paint

Medium: Glue (new rock paint)

Basal material: Kozo paper (5 momme, 10 momme, 15 momme, 20 momme)

Dosa concentration: 3 %, 4 %

Number of applications: 1 surface surface

The mulberry paper made of long and strong fibers is durable, smooth and supple. It is a very versatile paper with a wide range of basis from thin to thick.

In both mulberry paper, the density is 3%, and the alum water is moderate, and at 4%, the water repellent seems to be strong, and it plays a little coloring material. Even 15 momme and 20 momme have a density of 3 %, the sizing effect is 3 %.

Thick paper with 15 momme or more is difficult for dosa to penetrate, so be careful not to apply unevenness, such as applying and adjusting the number of times on both sides.

◾ White hemp paper

Verification environment: September 2, 2022 Room temperature 22.7 degrees Humidity 60%

White hemp paper is a thick but flexible basal material that uses tough hemp fibers and mulberry for paper fees.
In the case of raw, the penetration is stronger than the mulberry paper. There are also aspects that are easy to express color tones and shades of shades using their characteristics.
Like a thick mulberry paper, please pay attention to unevenness when drawing dosa.
 

Next is a picture silk sample.

Of the three types prepared in this lab, we tested it with the thinnest 2 -丁 gius and the thickest three -sided gutter.

◾ silk

Verification environment: January 10, 2023 Room temperature 21 degrees humidity 50-55%

What is agar pull?It is a technique to fill the silk thread in agar and make it smooth.
Use the agar solution that is boiled and filtered. The concentration can be liked.
Once on the silk table, apply it to the picture silk with a brush while the agar solution is hot and dry it.
The point is to apply it while agar is a liquid. If the agar cools and hardens, it will not be gel even if it is heated again, so in the case of large works, apply it while boiling water, so be careful not to cool the solution.
After agar drying wellDosaPlease draw.
 

The samples you have seen are just an example, so the original samples that describe your own production environment and the information you need, such as the temperature, humidity, and the detailed information of the basal materials and color materials on the day of the processed day, not only the physical properties of the glue. By making it, it becomes more detailed data.

In the world of expression, the fun of being born from a coincidence is also interesting, but becoming a Dosa Master may trigger a clue to the excitement.

Art Materials Expert at PIGMENT TOKYO

Natsuko Shiraishi

Graduated from the Textile Design at Tama Art University. She is an artist who mainly works with original Washi paper and calligraphy.

Graduated from the Textile Design at Tama Art University. She is an artist who mainly works with original Washi paper and calligraphy.