What Is E-Ink? The Complete Guide to Electronic Paper Display Technology for ESL and Retail Digitalization

What Is E-Ink? How Electronic Paper Displays Work (Complete Guide)

E-Ink—also known as electronic paper—has become a critical technology in retail digitalization, electronic shelf labels (ESL), warehouse labels, and battery-powered IoT devices.
This guide explains exactly how E-Ink works and why it outperforms traditional LCD/LED in low-power and sunlight-readable applications.

What Is an E-Ink Display?

E-Ink is a reflective display technology designed to look like printed paper.
It does not emit light. Instead, it uses ambient light, creating a natural and eye-friendly viewing experience.

Primary Applications

Electronic shelf labels (ESL)

Warehouse picking tags

Retail digital signage

Smart office displays

E-readers such as Kindle

IoT devices with long battery life

How Does E-Ink Work? (Electrophoretic Technology)

At the core of E-Ink technology are millions of microcapsules filled with:

Positively charged white particles

Negatively charged black particles

Transparent fluid

When an electric field is applied:

White particles move to the top → the pixel appears white

Black particles move to the top → the pixel appears black

This process is called electrophoresis.

Why E-Ink Consumes Almost No Power

E-Ink technology only uses energy when the content changes.

No power is required to maintain an image

Power is only needed during refresh

After refresh, the particles “lock” in place through stable chemical and physical forces

This makes E-Ink the ideal choice for:

Smart labels

Dynamic price tags

Logistics tags

Any device requiring long standby time

Many ESL systems can run 3–7 years on a single coin battery.

How Do Color E-Ink Displays Work?

Today, E-Ink supports multiple types of color technologies:

1. CFA/COC (Color Filter Array)

A traditional black-and-white E-Ink layer is combined with a RGB color filter on top.
Advantages:

Affordable

Widely used in retail and signage

Limitations:

Lower brightness

Less vivid colors

2. ACeP (Advanced Color ePaper)

Each microcapsule contains multiple colored particles (cyan, magenta, yellow, black), each responding to different electrical signals.

Advantages:

More vivid and saturated colors

No color filter required

Suitable for premium signage

Limitations:

Slower refresh

Higher cost

E-Ink displays work by moving charged pigment particles inside microcapsules using electric fields.
They show stable images without power, remain readable under sunlight, and offer a paper-like experience that LCD and LED cannot match.

This makes E-Ink the ideal display solution for:

Retail ESL systems

Warehouse and logistics picking tags

Office signage

E-readers and portable devices

Low-power IoT applications