The predecessors of clay tablets are three-dimensional objects that were used for means of expression such as cones, disks, spheres, and cylinders. These objects were in the shape of "small clay tokens of various [forms] and sizes" and are thought to have been used in economical transactions and the industry of trade (Roaf 70). There have been hundreds of hollow clay spheres and tokens unearthed from the areas of Sumer and Elam, and cylinder seals have been found from the Uruk period, all of these objects being the precursors to written tablets. Since the numerical signs and symbols that are found impressed upon the seals and spheres are similar to the ones found on tablets, it has been proposed that the pictographs and written script were based on the earlier token system. .
The tablets that writing first appeared on were made of clay, the most plentiful raw material found in Mesopotamia. The clay was extracted from rivers where it had been deposited along the banks and the Mesopotamian people would collect the clay in order to process it for use. During these times clay had a vast array of uses such as for making pottery, mud-brick that would have been used in building and as tablets for use in writing. After the clay had been inscribed upon it would usually be baked in the sun or in a firing process (which was later established) and harden almost to the point of being indestructible. Thanks to the quality and durability of the clay used in Mesopotamia the origins of written language have been well preserved so that we now have great knowledge of the history of humankind. .
Once the Sumerians had a finished tablet they would then take a stylus which is a "reed whittled to a sharp point and used to produce the fine, curving lines of the early pictographs" (Kramer 131). The tablets were sectioned off into vertical columns and the Sumerians would write from top to bottom in the columns.