Look a little closer
See the mechanism
An electric field moves pigment particles
Read the diagram steps
White at the viewing side. For this black-and-white electrophoretic example, an applied field moves positively charged white particles toward the viewing side and negatively charged black particles away from it. The viewer sees mainly white.
Black at the viewing side. Reversing the field reverses pigment migration. Black particles collect near the viewing side and white particles move away, changing the visible surface. A suitable waveform updates the display; the image can then persist without continuous driving.
Selected positively charged white / negatively charged black pigment example. Other E Ink products use different pigments and architectures. Particle counts, paths and electrode spacing are schematic.
Diagram basis: E Ink: electronic-ink operation.
The white and black are physical pigments
In the two-particle microcapsule system described by E Ink, tiny capsules contain white and black pigment in a clear fluid. The two pigments have opposite electrical charges. The capsules keep those suspensions in small compartments across the display.
Electrodes create an electric field through the ink layer. Reversing the field changes which pigment is driven toward the viewing surface. White at the front makes that spot look white; black at the front makes it look black. The pigments are not being made and erased at each page turn.
Sources: E Ink
An addressable pattern becomes a page
The electronics control different parts of the display to arrange a pattern of light and dark regions. A letter is a pattern in the positions of the particles, rather than ink deposited on top of the cover glass.
This is an electrophoretic display: charged particles move through a fluid under an electric field. The diagram enlarges a small region of the ink layer to show that motion.
Sources: E Ink
Holding the pattern and lighting it are separate jobs
E Ink calls the ability to retain the image without continued display power bistability. Power is used to change the pattern, but the particle arrangement does not require constant refreshing just to keep a page visible.
That statement concerns the display image. An e-reader can still use power for its processor, wireless connection or front light. Bistability does not make the entire device electrically inactive while you read.
The pigment surface reflects light toward your eyes, like a printed page. In a dark room, the pigment does not become its own lamp. A device with a front light supplies illumination across the viewing surface so that the reflected pattern remains visible.
Sources: E Ink
The thing to remember
A page can remain visible after the electric drive stops because the display has already put the pigments where the image needs them.
What this example leaves out
This describes a two-pigment microcapsule E Ink system. Color E Ink and other electronic-paper technologies use different particle sets or constructions; update waveforms, grayscale control and transistor circuitry are simplified.
Sources & further reading
Source access dates are listed below. Manufacturer descriptions and patents support the specific constructions described, not every product.
- Electronic Ink — How it works ↗
E Ink · Retrieved 2026-10-17 · Two-particle microcapsules, oppositely charged white/black pigment in clear fluid, field-driven viewing change.
Two-pigment capsule construction; not all color electronic ink. - Benefits — E Ink Technology ↗
E Ink · Retrieved 2026-10-17 · Bistability/image retention without display holding power; reflective viewing.
Display layer only, not total e-reader power; health/marketing comparisons excluded.