Some chipless tags use plastic or conductive polymers instead of silicon-based microchips. Other chipless tags use materials that reflect back a portion of the radio waves beamed at them.

A computer takes a snapshot of the waves beamed back and uses it like a fingerprint to identify the object with the tag.

Companies are experimenting with embedding RF reflecting fibers in paper to prevent unauthorized photocopying of certain documents. Chipless tags that use embedded fibers have one drawback for supply chain uses: only one tag can be read at a time.