Form factor

The form factor of a tag refers to its shape, size, packaging, and handling features. To a large extent, a tag’s form factor is determined by the characteristics such as power source and functionality. Some important aspects regarding a tag’s form factor include the size of the tag, the weight of the tag, and the method by which the tag is affixed to and removed from its associated object.

Tags typically vary in size from smaller than a postage stamp to about the size of a common document stapler. Active tags typically are significantly larger and heavier than passive tags because they have an onboard power supply. Tags that integrate environmental sensors are also larger and heavier than those without this functionality. While increasing the computing functionality of a tag increases its cost and power requirements, it may not have an impact on its form factor because the microchip on a passive tag is one of the tag’s smallest components. On most passive tags, the largest component on the tag is its antenna.