I have, and I'll show it: From Textile Printing to Sealing

Did you know that the first stamps created by humans were likely used for printing clothing? People didn't have postage stamps around 8500 BCE, but they did cut predecessors of seal stamps from various materials to decorate clothing and probably their own bodies with earth-derived pigments like ocher. These early stamps featured geometric patterns. However, around 6000 BCE, a small revolution took place in the region known as Northern Mesopotamia, located in the headwaters of the Euphrates and Tigris rivers. In this area, people likely began pressing personal talismans into small clay beads: The first seal was born, and the talisman evolved into a personalized seal stamp.

It may have served as proof of ownership, perhaps after exchange transactions.