Ancient scribes wrote cuneiform by pressing a reed stylus into soft clay tablets, creating the characteristic wedge‑shaped marks.

The Main Tool: Reed Stylus

  • The primary tool was a stylus made from the hollow stalk of a reed, cut at an angle so its tip had sharp edges.
  • When pressed into moist clay, this angled tip produced the triangular, wedge‑shaped impressions that give cuneiform its name (from Latin cuneus , “wedge”).

How It Was Used on Clay

  • Scribes first shaped a small tablet of wet clay, often sized to fit comfortably in the hand, and then pressed the stylus into the surface, one wedge at a time.
  • By rotating and tilting the stylus, they could make vertical, horizontal, and diagonal wedges, combining them into different signs.

Other Supporting Tools

  • To prepare and finish tablets, scribes likely used simple tools such as slats, cords, and smoothing implements to rule guidelines and neaten the clay surface.
  • In modern demonstrations, museum educators sometimes replace the ancient reed stylus with a popsicle stick or similar object to imitate the same wedge effect in clay.

TL;DR:
Cuneiform was written on soft clay tablets using a cut reed stylus whose angled tip, pressed into the clay, formed the distinctive wedge‑shaped signs.

Information gathered from public forums or data available on the internet and portrayed here.