Today’s Tech. Rev. describes an epaper technology developed by Nemoptic that the company hopes will be cheap and efficient enough to be used as disposable unit price tags, replacing the ubiquitous paper unit price tags currently used on store shelves. Very cool.


A paper unit price tag. Image from

About 20 years ago, I came up with an idea for wireless shelf tags (just the concept, with no idea how to build a working prototype) and showed it to my mother, who was a manager in a supermarket at the time. Given prices and technology at the time, my thought was the tags would be permanent, not disposable and would require an external power source. I explained to my mother the labor savings from having a tag that could be updated without requiring a clerk to print and attach it. I also explained how the tags would always display the same price as the scanner at the cash register because both would get price information from the same database. (This doesn’t necessarily mean the price is correct though, just consistent.)

Her reaction was interesting.

First, she wanted to know how the tags would be attached to the shelf. I said probably with a couple of screws. She explained to me that the tags had to be easily moved as shelf space needs changed. This is easy to do with paper tags with the current plastic tag holder. She was afraid that securing electronic tags to the shelf would make it too hard to move them.

Then she said the biggest problem with paper tags is not that they need to be updated. It was that they constantly need to be replaced because they are stolen by customers. Really!

Even if my electronic tags were screwed to the shelf and were useless when disconnected from the shelf, they would be an irresistible target for malicious thieves. My mother said that sometimes the only difference between a profitable store and a money losing one (in the same chain) was the amount of shrinkage. So preventing theft and damage is a key consideration in selecting materials used in a retail environment.

In response, I proposed replacing the tag with a bar the full width of the shelf. That way it would never have to be moved. The clerks would “move” a price tag by sliding it along the bar. She then asked how durable the display bar would be. Even if customers couldn’t steal them, she was sure some would attempt to pull them off the shelves.

She also wanted to know how a clerk would move a tag from one shelf to another and how much training the clerks would require to do this. And she wanted to know, how would clerks prevent malicious customers from watching them and then copying those actions themselves throughout the store. The user interface and security issues stopped me from pursuing the idea further.

The advantage of the paper shelf tags was that they were easy to move and cheap to replace. Factors like easy to update and absolute accuracy were not important to her. So even if disposable epaper unit price tags are less expensive than paper ones, they may cost more to implement, if customers take them and you need more of them.