Is Sumi Ink Waterproof – Our Breakdown!

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The popularity of Sumi ink just keeps on increasing with each month that passes with people using it for general artwork and writing more and more as people realize just how cheap and reliable Sumi ink actually is. With the popularity of Sumi ink constantly growing at a solid pace, more and more people are asking a number of different questions to ensure that they are getting the most out of their ink during use.

One of the more popular questions that we have seen people asking over and over again is if Sumi ink is waterproof or not. With so many people asking this and so many people confusing Sumi ink with India ink (we have gone over the differences in this article) we have decided to publish this dedicated article going over the waterproof properties of Sumi ink.

Our hope is that we are going to be able to help our reader who do use Sumi ink as the formula is not as straight forward as with India ink and there are a few conditions that you have to factor in when it comes to the formula being waterproof or not. Thankfully though, these are simple and easy to consider for the vast majority of arts and crafts work so it shouldent cause any issues with helping you find the perfect Sumi ink for you.

Is Sumi Ink Waterproof?

Although the majority of the commercially available Sumi ink formulas on the market these days are waterproof and will hold up to water very well once dry, there are a few exceptions. This is due to one of the key ingredients in Sumi ink being animal glue and although most formulas do use gelatin that allows the ink to dry waterproof, some formulas do use albumin or casein that is not waterproof.

This is why you are able to purchase a commercially produced non-waterproof Sumi ink if needed although their use cases do tend to be much lower than an actual waterproof Sumi ink while being almost the come price. Due to this, the majority of people do usually end up with a waterproof Sumi ink formula but we just wanted to make our readers aware that you do have to check the ink bottle prior to purchasing it to double check.

On top of this, homemade Sumi ink is also becoming more and more popular due to it being quick, easy, and cheap to produce in your own home. Similar to the commercial grade Sumi ink products, the waterproof qualities of your homemade Sumi ink ar going to depend on the ingredients that you use, largely the specific type of animal glue.

On top of this, some people also report that a commercial waterproof Sumi ink product is not actually waterproof during use but this is almost always due to user error in the application of the ink. You have to wait a few minutes for your Sumi ink to actually set before its waterproof qualities will take hold. Due to people living busy lives these days, they often focus on getting the job done as fast as possible rather than letting their mediums dry prior to layering.

Is Sumi Ink Water Soluble?

The majority of the modern commercial Sumi ink formulas on the market are not water soluble once dried but a small number of them are. This is usually due to additional ingredients being added to the ink formula to give it a slightly different color or effect once dry but these formulas are definitely in the minority.

As we touched on above, there are also a number of non-waterproof Sumi ink formulas that clearly advertise themselves as not being waterproof that tend to be water soluble too so keep this in mind when choosing the right ink formula for you. The vast majority of the waterproof Sumi ink formulas that clearly market themselves as being fully waterproof once dried are not water soluble though and can have additional water added on top of them once their initial pigments are dried without issue.

Can Sumi Ink Be Diluted With Water?

Although some people do dilute their Sumi ink with water, we usually recommend against this for two reasons. First, Sumi ink is not water-based like India Ink, it is based around animal glue as its binding agent and both perform slightly differently to each other. If you do need to dilute your Sumi ink then try to use an animal glue that is already used in the formula for optimal performance.

Second, adding water to your Sumi ink in an attempt to dilute it can end up causing you problems with the actual consistency and its setting process. Rather than just taking a couple of minutes to set and become a permanent ink, the addition of water can end up causing it to take considerably longer. If you are working on a time-sensitive commission that needs layering then this is less than ideal as it slows you right down when time is essential.

Thankfully, the vast majority of the decent Sumi ink formulas on the market these days have been optimized to a level where there should be no need to dilute them anyway. The formulas have been specifically designed for use the way they ship and they have also been tested over and over again to ensure that they deliver the highest possible quality to you, the end user.

How Do You Seal Sumi Ink?

Although it is not essential to seal Sumi ink as the permanent nature of the ink formula once dried is usually enough for the majority of people, some people do use a gloss lacquer spray to seal the ink for specific types of artwork. That said though, different Sumi ink formulas tend to perform differently to different types of gloss lacquer so having a quick Google search for the specific lacquer people use for your brand of Sumi ink is probably worth the time.

The majority of gloss lacquer sprays tend to perform well with Sumi ink though especially once dry and the waterproof nature of most ink formulas should prevent you from having any issues with running in most cases. As with most things when it comes to art though, it is better to be safe than sorry so we would still recommend that our readers have a quick Google search to double check that they are using two compatible products.


That brings our article going over if Sumi ink is waterproof to a close and as we have touched on throughout our article, there is no straight answer and you have to factor in a few variables when it comes to the waterproof nature of Sumi ink. Provided you opt to go with a waterproof Sumi ink formula though, you should have no major issues provided that you let your ink dry for a few minutes after applying it to your paper or canvas.