PIGMENT TOKYO carries various types of animal glue as painting mediums.
KOEI CHEMICAL CO., LTD., located in Himeji City, Hyogo Prefecture, specialized in producing gelatin and collagen peptides. They manufacture all the animal glue available in our store.
In the previous article, "How PIGMENT TOKYO's Original Animal Glue is Made—The Collagen and Gelatin Industry Today— Part 1" we interviewed the company's CEO, Mr. Takashi Fukushima, about animal glue, the current state of the industry and KOEI CHEMICAL CO., LTD. 's contribution to this field.
In the second part, I will share insights from the tour of the animal glue manufacturing process led by the managing director, Mr. Hiroyuki Shimizu.
Gelatin and animal glue as both food and industrial products are produced through the following processes.
For this tour, they prepared two types of animal glue made from finely chopped dried cowhide and fish skin (sea bream).
To begin, the dried cowhide is chopped into small pieces and soaked in water before being boiled.
Typically, the extraction process involves multiple iterations and blends various types of glue with different jelly strengths. However, for this instance, we only did the initial extraction.
The number of extractions varies depending on the type of animal glue, but once the pot is heated, the extraction process is very time-consuming, requiring continuous operation for 24 hours.
The right is cowhide and the left is sea bream skin.
From here, they will be boiled for hours.
As with cooking, lye and oil will float to the surface when these are cooked, so those are carefully scooped up with a ladle.
Based on these pictures, it looked like they were cooking.
It also smelled as if they were making soup.
They periodically measure the concentration of the animal glue with a densitometer while maintaining a specific temperature.
Unlike edible gelatin and collagen peptides, which are produced in large quantities, the original Japanese animal glue requires expert craftsmanship. For example, this particular process took eight hours, from lighting the fire to the first extraction.
The boiling for ox glue started at 7:30 a.m. while fish glue started at 10:30 a.m.
Here is when the first extraction is done. It looks like soup stock. The soup is moved to a different place and chilled down to our skin temperature before filtration.
Extracted soup
This is the filtration process in a filtering machine.
A ceramic funnel is equipped with a pulp filter, which uses vacuum pressure to filter the impurities.
Fish glue undergoes the same filtration process.
The glass container below is fitted with a device that creates a vacuum inside the container. This allows for efficient filtration.
Once the heat is removed, the animal glue solution is poured into separate containers for cooling.
For actual product manufacturing, after the cooling process, they are cut into pieces and dried on a special wire mesh in a factory’s room.
Drying animal glue at KOEI CHEMICAL CO., LTD.
Following this, they will measure animal glue's jelly strength and components.
The left photo below shows the machine used at KOEI CHEMICAL CO., LTD to measure jelly strength.
Dissolved animal glue is poured into a special jar and cooled down to a jelly form. Then, a plastic rod is used to measure the strength of the jelly by applying pressure to it.
The right photo shows the jar used for this test.
The jar is strictly regulated by JIS (Japanese Industrial Standards).
It is designed to measure both food and industrial products, depending on whether the left or right side is used.
Since original animal glue is made from various raw materials depending on the time of year. Therefore, instead of focusing on keeping the numerical value consistent, as is done with large-scale products, the manufacturing approach might be different.
The factory would skip the process of "9. Mixing" (according to the chart at the beginning of this article), and the final inspection is conducted before the product is shipped in stick form.
As described above, the production of animal glue involves a lengthy process. At KOEI CHEMICAL CO., LTD, there are samples and prototypes of raw materials, but we couldn't introduce all of them here. Although these materials are not currently their main products, we were able to witness firsthand their extraordinary commitment to their products.
After this interview, we returned to the lab at PIGMENT TOKYO to conduct the second and third extractions of cowhide with the first extraction that we brought back.
First, we cut the solidified animal glue into pieces and placed them in a container. Similar to the drying process at KOEI CHEMICAL CO., LTD, we placed the glue in a jelly-like state, on a mesh metal surface and allowed it to dry at room temperature.
Drying fish glue
We followed a process similar to that used at KOEI CHEMICAL CO., LTD. First, we boiled the raw material from the first extraction in water until it reached the appropriate viscosity for adhesive. The second extraction took about 7 hours and the third extraction took another 7 hours.
(Originally, the mixture is boiled down to the proper thickness using a desitometer or a similar device.)
After a simple filtration process, the liquid was poured into a metal tray, cut into thin strips and then dried.
Drying animal glue. The left one is ox glue made by the second extraction, and on the right is fish glue.
Drying animal glue. The left one is ox glue made by the second extraction, and on the right is fish glue.
Although this was a simple process that did not involve measurement of product level or extraction, we could still make animal glue that looked as good as the one manufactured in KOEI CHEMICAL CO., LTD.
From left to right: first extraction, second extraction and third extraction animal glue. You can see the difference in transparency.
PIGMENT TOKYO is dedicated to promoting the techniques and knowledge accumulated by artisans and artists over a long time. We believe that animal glue has potential beyond just Japanese painting, including its ability to mix with other water-based mediums.
Therefore, by all means, we invite you to explore the diverse possibilities of expression across various painting styles using our high-quality Japanese products.
[Corporate Information]
KOEI CHEMICAL CO., LTD
33 Yobe-ku Kamiyobe, Himeji-shi, Hyogo,671-1262 Japan
TEL：079-273-2001
FAX：079-273-2010
WEB：https://www.koei-chem.com/index.html
*Animal glue manufactured by this company is exclusive to PIGMENT TOKYO's products.
You may purchase them through PIGMENT TOKYO physical and online stores.
PIGMENT TOKYO
Translated by Atsumi Okano, Nelson Hor Ee Herng
PIGMENT TOKYO Art Materials Experts
Art Materials Expert at PIGMENT TOKYO
Akira Oya
Born in 1989 in Tokyo. Master of Fine Art and Design at Nihon University College of Art.
He also continues his career as a visual artist.
Born in 1989 in Tokyo. Master of Fine Art and Design at Nihon University College of Art.
He also continues his career as a visual artist.