E-Ink vs. LCD vs. Paper Price Tags: Which Works Best in a Display Case?

If you're moving away from handwritten or printed tags, you'll quickly run into two display technologies: E-Ink (electronic paper) and LCD. Both can show a price that changes on command, but they behave very differently inside a lit display case. Here's how they compare with each other, and with the paper tags you're probably using now.

The quick comparison

E-Ink: built to look like paper

As E Ink explains, its displays use charged black and white particles that move to the surface when an electric field is applied, then stay put. Because the screen is bistable, it only draws power when the image changes.

That has two big benefits in a store:

• Battery life measured in years. Wikipedia's overview of electronic shelf labels notes that e-paper needs power only during updates.
• Readability like printed paper. E-Ink reflects ambient light instead of emitting it, so bright case lighting makes it easier to read, not harder.

The trade-offs are limited color and slow refresh. That's irrelevant for a price that changes a few times a day, but rules out video or animation.

LCD: bright, colorful and power-hungry

LCD tags and small screens can show full color, logos and motion. Electronic shelf label maker Minew points out that LCDs refresh faster and support far more color, but need a backlight, use more power, and can suffer from glare in bright light. (Minew sells both kinds of tags, so treat its comparison as a vendor's view.)

Wikipedia also notes that early segmented LCD price tags, the calculator-style kind, had trouble displaying some letters and needed constant power to hold an image.

In a jewelry case under strong spotlights, glare and reflections can make LCD screens harder to read from the customer's side of the glass. LCDs are better suited to wall menus and promotional screens than to small tags beside each item.

Paper: still fine for some stores

Paper isn't obsolete. If your prices rarely change, paper tags are cheap, flexible and readable. The problems start when prices move often:

• Labor. Every change means printing, cutting and swapping.
• Accuracy. A tag that didn't get updated is the most common cause of shelf and register mismatches.
• Timing. You can't reprint a case full of tags every time the gold price moves.

Which fits which store?

• Coin and bullion counters: prices follow the market through the day, so E-Ink tags tied to a price feed make the most sense.
• Jewelry cases: E-Ink suits small tags beside each piece; readability under case lighting is a strength.
• Pawn shops: E-Ink for gold and silver jewelry that moves with the market; paper may be fine for slow-changing general merchandise.
• Promotional signage: LCD or larger screens work well for wall displays and featured items, where color and motion help.

Questions to ask a vendor

1. Are the tags E-Ink or LCD, and how many colors do they show?
2. What battery life do you claim, and at what update frequency?
3. How do the tags look under strong case lighting, from a customer's angle?
4. Can I see a sample tag in my own case before committing?

For how the whole system fits together, see our explainer on how electronic shelf labels work.

Sources

• Wikipedia, Electronic shelf label
• E Ink, How E Ink works
• Minew, Differences among LCD labels and E-Ink labels