A TECHNOLOGY BRAND BY KUNMUK

Teal ink flowing against a black background, an abstract brand visual

FUNCTIONAL INK. NEW POSSIBILITIES.

BITTER INK®

A new function. On the surface.

Bitter-taste functionality through printing and coatings.
Discover what your next product could become.

Explore our technology
A TECHNOLOGY BRAND BY KUNMUKSCROLL TO EXPLORE EST. 2025

TECHNOLOGY

SMALL LAYER.
NEW POSSIBILITIES.

A thin layer. A new way to think about your product.

BITTER INK is Kunmuk’s technology brand for incorporating bitter-taste ingredients into printing and coatings.
We review your material and use conditions, then work together to develop an appropriate application.

BITTER FUNCTION

Bitter-taste functionality

We define the intended function, such as deterring oral contact,
and review the relevant conditions of use.

SURFACE & MATERIAL

Material compatibility

We assess application feasibility and methods
based on substrate and surface characteristics.

PRINT & COATING

Print & coating collaboration

Our application experience with offset, UV and gravure
informs discussions about the production process.

TEST & DEVELOP

Sample development & evaluation

We agree on evaluation criteria, such as functional performance,
uniformity and adhesion, and assess the samples.

SURFACE TO POSSIBILITY

One technology. Different possibilities.

From printing and coatings to the products we use every day.

Concept image of transparent film and a printing roller
01 / PRINT & COATINGConnecting materials and processes
Concept image of transparent film over wood, metal and ceramic material samples
02 / PET CARERethinking everyday surfaces
Concept image of paper samples with tactile spot coating
03 / SENSORY PRINTAdding a sensory dimension to stories

Concept images illustrate potential applications; they are not photographs of finished products.

REGISTERED BRANDBITTER INK: trademark protection
PATENTED TECHNOLOGYKorean Patent No. 10-2761689
REAL APPLICATIONSApplications in books & pet-care products

PROTECTED INTELLECTUAL PROPERTY

Our technology. Our brand.
Protected by intellectual property rights.

BITTER INK’s technology and brand are protected by patent and registered trademark rights.

01 / PATENT PROTECTION

Patent-protected technology

KR 10-2761689

Ink composition comprising a non-toxic bitter-tasting additive, and printed materials comprising the same.

Patent holder · Kunmuk Co., Ltd.
U.S. patent application pending
View patent certificate
02 / TRADEMARK PROTECTION

Trademark-protected brand

Bitter INK®

BITTER INK is a registered trademark. The brand name and identity are protected by trademark rights.

Application No. · 40-2025-0107592
Registration No. · 4026080290000
KC certification markKC CERTIFIED

BITTERBOOKS / CHILDREN'S PRODUCT SAFETY

Two picture books for children.
Safety standards verified through KC certification.

The BitterBooks picture books “My Fingers, Kong’s Toes” and “Inom Seonsaengnim” have KC certification. We value not only the stories we create, but also making products that meet the applicable children’s product safety standards.

My Fingers, Kong’s ToesKC-certified picture book
Inom SeonsaengnimKC-certified picture book

OUR VISION

BEYOND THE ORDINARY

A Different
Kind of Ink.

Rethinking familiar surfaces.

From printing that adds color to printing that adds function.
BITTER INK connects the sensation of bitterness with new possibilities for products.
We continue to develop and evaluate applications that can bring this difference into everyday life.

DISCOVER

Discover the opportunity.

We look at how products are used
and identify surfaces where a function could help.

CONNECT

Connect technology and products.

We consider materials alongside printing and coating processes
to turn an idea into a development project.

REFINE

Refine the application.

We use samples to understand opportunities and limitations,
then refine the approach for the product.

APPLICATIONS

FROM INK.
INTO LIFE.

Where technology becomes an everyday product.

Kunmuk applies BITTER INK to products under its own brands,
building experience from development through commercialization.

01 / PET CARE
BitterCare
Product application concept image
APPLICATION CONCEPT

Bitter-taste functionality for everyday surfaces

BitterCare

An adhesive product developed to help deter unwanted chewing by dogs.
This application uses a bitter-taste coating on transparent PET film.

Explore the brand
02 / PUBLISHING
BitterBooks
Product application concept image
APPLICATION CONCEPT

Printing that connects stories and sensory experiences

BitterBooks

An application of bitter-taste printing to a selected picture-book page.
It connects storytelling with a new sensory experience.

Explore the brand

WHAT'S NEXT?

Your next product
could be our next application.

PARTNERSHIP

LET'S MAKE
THE NEXT DIFFERENCE.

We welcome partners who want to explore new product possibilities.

01

Product application development

Manufacturers · Brand owners

For companies exploring bitter-taste functionality,
we review materials, intended use and the scope of sample development.

02

Printing & coating collaboration

Printers · Coaters · Material companies

With partners who bring process expertise,
we review material compatibility and production feasibility.

03

Joint business development

Product concepts · Joint development · Technology-use discussions

Starting with new use cases and product ideas,
we discuss development roles and commercial terms.

HOW WE WORK

From an idea to a defined development project.

  1. STEP 01

    Define the application

    Share the product, material and use conditions

  2. STEP 02

    Review feasibility

    Discuss process conditions and sample scope

  3. STEP 03

    Sample development & evaluation

    Evaluate against agreed criteria

  4. STEP 04

    Discuss commercial terms

    Discuss supply, production and partnership terms

Feasibility and performance require a product-specific review. Development costs, timing and minimum quantities depend on the agreed scope.
Safety and applicable requirements must be assessed for the final product’s intended use and destination market.

QUESTIONS

Questions
before we begin.

Which materials can you work with?

We have application experience with paper and PET film in our own products. For other materials, we review surface characteristics, printing or coating methods and conditions of use before assessing feasibility.

Can I purchase the ink directly?

We currently welcome inquiries about product-specific application development and partnerships. The ink or coating approach and availability for supply are discussed individually after reviewing your application requirements.

Can we talk while an idea is still taking shape?

Yes. We can discuss a potential collaboration before detailed specifications are available. Tell us about the product and the problem you want to address so we can define the scope of a review.

Are the technology and brand protected?

Yes. BITTER INK’s technology is protected by Korean Patent No. 10-2761689, and the registered BITTER INK trademark is protected by trademark rights.

CONTACT US

IT STARTS
WITH YOU.

Your product’s next possibility.
Let’s talk about it.

The product you have in mind. The problem you want to solve.
A collaboration can start with a simple idea.

KUNMUK CO., LTD.
BITTER INK® / TECHNOLOGY & PARTNERSHIP
PARTNERSHIP EMAILbitterink@naver.com

Our team will review your inquiry and reply to the email address you provide.

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BITTER INK / PARTNERSHIP

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