Trivia About Ink Paste (Indei)

An essential item for calligraphy works is ink paste (Indei).
Here, we will introduce methods to restore ink paste when it hardens or becomes loose and sticky, as well as tips for daily care.

What Is Ink Paste (Indei)?

Ink paste is said to be made by mixing cinnabar (mercury(II) sulfide) as the main ingredient with plant fibers called “mogusa” and oil.
Ink paste is produced in China, and the details of its composition are unknown because the recipe is handed down secretly from artisan to artisan.
The ink paste from “Shanghai Xiling Seal Society” is especially famous.
Since cinnabar (mercury(II) sulfide) is toxic to the human body, be careful not to ingest it.

■ How to use ink paste ＞＞

When the Ink Paste Hardens

If the ink paste is left unused for a long period or stored in a cold place, it can become hard and difficult to apply to your seal.

When Only the Surface Has Hardened

If only the surface has dried and hardened, mix the firm surface and the softer inside thoroughly from the bottom.
Warming a metal spatula slightly before mixing will make the process easier.

When the Entire Paste Has Hardened

Warming the ink paste will soften it.
Warm it gradually while checking its condition.
Using a slightly warmed metal spatula will also make mixing easier.
Here are four methods you can try:

1. Place it near a heater to warm it slowly

2. Use a hair dryer to gently warm the bottom of the container from a distance

3. Put the ink paste in a heat-resistant plastic bag and warm it in lukewarm water (double-boiler method)

Remove the ink paste from the container and place it in a heat-resistant plastic bag. Tie the bag securely and immerse it in lukewarm water.
Once it softens, knead it gently through the bag.
After mixing, return it to its original container.

4. Mix in ink paste oil

There are special oils available for ink paste, and mixing in a small amount can help soften it.
You can also use castor oil or semi-solid grease, but oil specifically made for ink paste, sold by manufacturers, is more reliable.
*Please note: our online shop does not carry these oils.

When the Ink Paste Becomes Sticky

During hot summer months, ink paste can loosen or the oil may separate, making it sticky.
Here are two methods to address this:

1. Absorb excess oil with a tenugui cloth or bleached cotton

Gently dab the surface of the ink paste with a tenugui cloth or bleached cotton to absorb excess oil.
Placing a piece of cloth cut to fit the surface on top overnight is also effective.
If oil has separated from the paste and it’s used as is, the oil may seep out around the seal impression over time.
Be sure to absorb as much excess oil as possible before using.

2. Chill it briefly in the refrigerator

Chill the paste in the refrigerator for a short time, then mix it well before use.
Cool it gradually while observing its condition.

Daily Care and Storage Tips for Ink Paste

Each time you use ink paste, make sure to knead and mix it well.
Even if you don’t use it for a long period, mixing it about once a month can prevent hardening and oil separation.
When storing, cover the ceramic container with its lid and place it in the accompanying box.
Ink paste becomes sticky in heat and hard in the cold.
We recommend storing it in a location with moderate temperature.

Why Are Ink Paste Containers (In-gō) Usually Ceramic?

Oil in the ink paste can evaporate easily, but ceramic containers help prevent this evaporation, which is why they are commonly used.
Some containers also come with a paulownia wood box, which helps maintain consistent humidity inside and prolongs the life of the ink paste.

“Shippō Ink Paste” — Free of Harmful Heavy Metals

“Shippō Ink Paste” is made using organic and inorganic pigments that are completely free of harmful heavy metals, following traditional methods.
It is an environmentally friendly, safe, and human-friendly ink paste.
Because it uses high-quality mogusa and fine oil that do not harden easily or separate, problems like hardening or oil separation are rare.
It also features a gentle sandalwood scent that calms the mind during use.

See details on “Shippō Ink Paste”

Summary

We’ve shared some useful tips about ink paste.
Daily care is essential to make your ink paste last a long time.
Be sure to mix it well each time you use it, and even if you don’t use it often, mix it at least once a month.
If it becomes hard or loose and sticky, try the methods introduced above.

Click here to see the ink pastes introduced on Shoyu Online »