Cuneiform
Early Dynastic cuneiform (circa 2500 BC)

In the mid-3rd millennium BC, a new wedge-tipped stylus was introduced which was pushed into the clay, producing wedge-shaped cuneiform. This development made writing quicker and easier, especially when writing on soft clay. By adjusting the relative position of the stylus to the tablet, the writer could use a single tool to make a variety of impressions. For numbers, a round-tipped stylus was initially used, until the wedge-tipped stylus was generalized. The direction of writing was from top-to-bottom and right-to-left. Cuneiform clay tablets could be fired in kilns to bake them hard, and so provide a permanent record, or they could be left moist and recycled if permanence was not needed. Most surviving cuneiform tablets were of the latter kind, accidentally preserved when fires destroyed the tablets' storage place and effectively baked them, unintentionally ensuring their longevity.
startend:quotation, detectable_content:postscript