Electronic shelf labels, LCD versus e-paper

An e-paper (electronic ink) display is the default choice for shelf prices: the image holds without power, it reads well under store lighting, and a coin cell lasts for years. LCD is kept for zones where content moves or changes non-stop, such as video strips or animated promotions.

They are tools for different jobs, not a better and a worse version of the same thing.

This page compares the two displays using the public figures we could check, retrieved on 9 November 2026. Several come from e-paper or component vendors, and we say so each time. For the whole system (radio, gateway, battery), the overview is in electronic shelf label technology.

How each one works

E-paper is a reflective, bistable display: every dot keeps its state without power and only uses energy at the moment it changes. Wikipedia summarises it that way and adds that it offers a wider viewing angle than most light-emitting displays. A short definition lives in the glossary.

LCD is a liquid-crystal display that modulates light. In its usual form (backlit TFT) the image has to be redrawn continuously: the 2017 Electronic Design article mentions roughly 50 times a second even when nothing changes. Variants built to save power exist, such as memory-in-pixel (MIP) or transflective LCDs, which reflect ambient light. When someone in retail says “LCD label”, ask which of these they mean, because power draw varies enormously between them.

Quick comparison

Criterion	E-paper	LCD
Power with a static image	Practically zero	Continuous. From 2 µA (MIP) to 8.5 mA (1.3” transmissive TFT) in one DisplayModule example
Power when changing	Short peak: 15 mJ per full black-and-white refresh in the same example	Little more than at rest
Change time	900-1,200 ms (full black and white); 12-15 s (multicolour)	8-25 ms response in the examples cited
Video and animation	No	Yes
Viewing angle	Close to 180° according to Pervasive Displays	Depends on the panel; we found no comparable figure from a neutral source
Direct sunlight	Fine, it is reflective	Poor on backlit LCD; better on transflective
Low light	Needs ambient light; below about 50 lux, reading a reflective screen causes eye strain (DisplayModule)	Good if backlit
Cold	Refresh gets slower and uses more energy	Response slows down too
Colours	Black/white, red or yellow are common; multicolour panels are slower	Full colour
Typical supply	Coin cell, years	Mains or rechargeable battery

Table sources: Electronic Design (6 Jun 2017), DisplayModule (26 Feb 2026), Wikipedia. The first two are display suppliers, so treat their numbers as orders of magnitude, not a guarantee for any given model.

Power and battery

This is the difference that decides almost everything. With LCD, the energy bill is set by time switched on; with e-paper, by the number of changes.

DisplayModule’s example gives an e-paper panel 15 mJ per full black-and-white refresh and 3.5 mJ for a fast partial one, with zero draw between changes. A small MIP LCD uses about 15 µW at 1 Hz; a 1.3-inch transmissive TFT, 8.5 mA static. The units are not comparable at a glance, but the conclusion is: the TFT cannot run on a coin cell for years, and e-paper can. Real label datasheets agree: SoluM’s Newton Pro publishes more than 5 years on one CR2450 cell and more than 10 on two, at two updates a day and between 0 and 40 °C.

Between the two there is a wide grey zone. A module maker (Soldered) puts e-paper as the most efficient option below roughly four updates a day and calls LCD the better pick above about 600; it says nothing about what happens in between. That is a vendor’s estimate, not an independent measurement, but it is a useful guide: a label whose price changes once a day sits firmly at the e-paper end, and a screen that rotates ads every few seconds is well past the LCD threshold.

How cold and frequent updates affect battery life is covered in electronic shelf label batteries, and what changes in freezers and chilled cabinets in labels for freezers.

Reading it: distance, angle and light

We will not give a table of metres per font size for 1, 2 and 3 m, because we found no public source measuring both technologies under the same conditions, and an invented figure is worse than none. What does hold up:

• At 1 m, a customer leaning towards the product reads either type if the layout is right. The size of the price digits matters more than the technology.
• At 2-3 m, legibility depends on contrast and type size. Wikipedia reports a lab prototype (Retina E-paper) with about 80% reflectance and 50% optical contrast; treat that as a research ceiling, not what a commercial label ships with, where the specific panel rules. A backlit LCD emits its own light, which helps in dark spots such as a refrigerated display with no lighting.
• At an angle, e-paper behaves like printed paper: it looks the same from the side. With LCD it depends on the panel type; ask the supplier for a test on your real shelf.
• In strong light, e-paper wins. Electronic Design claims LCDs become “virtually unreadable” in direct sun. It is rare indoors, but real next to shop windows or in garden centre and DIY outdoor areas.

The practical advice is to test: one label of each type, at real shelf height, in your most difficult aisle.

Update speed and video

This is e-paper’s limit. DisplayModule gives 900 to 1,200 ms for a full black-and-white refresh, 250 to 300 ms for a partial one and 12 to 15 s for multicolour panels. Partial refreshes are faster but leave traces of the previous image if overused, so they are alternated with a periodic full refresh.

For a price update it makes no difference whether it takes one second or ten; the platform does it in the background. For playing a product video it is nowhere near good enough. LCDs, with response times in the tens of milliseconds, move smoothly. That is why video and animation are associated with LCD shelf strips or rails, a different product from the price tag and used for advertising rather than operations. We only mention them in general terms here; we do not analyse specific models.

Colour is a variation of the same trade-off. Three- and four-colour e-paper panels exist, but at the cost of longer change times. For when colour pays off, see colour in electronic shelf labels.

Cost per unit

We do not publish per-label prices. E-paper and LCD prices depend on size, volume, whether they include a radio, and the software contract, and the public listings we saw are not comparable with each other. What can be said on engineering logic is what costs more beyond the label itself:

• E-paper labels clip onto the shelf edge and need no wiring of their own; the investment is the gateway and the platform.
• Shelf LCD displays need power, either by cable or a rechargeable battery, which adds installation work or maintenance.
• Battery life feeds into maintenance cost: replacing cells in thousands of labels is real labour.

To run this with your own numbers, use the total cost calculator with quotes from your suppliers.

When to choose each

E-paper: shelf prices, gondola labels, offers that change a few times a day at most, chilled cabinets (with the caveat about cold and choosing the right model), and any spot without a power socket. It is the technology described in what an electronic shelf label is.

LCD: rails with video content, promotion zones with rotation, gondola ends with dynamic messages, places where power already exists and the advertising space justifies the spend.

Both, each in its place: the most common outcome. The price goes on e-paper; the impact zone, if there is one, on LCD. Mixing them for the same job rarely pays off.

Limits of this comparison

The power and timing data come from two display vendors’ articles, one from 2017 and one from February 2026, not from an independent test of commercial LCD and e-paper labels. Wikipedia describes laboratory technologies in some of its examples, not shop labels. Wherever a figure comes from a single manufacturer, we say so. If you have your own measurement or a datasheet that contradicts any of these figures, we will review it and date it.