Knowledge of ancient Middle Eastern history is largely based on written records preserved on clay tablets, but tablets have often been separated from other archaeological artefacts, with erratic consequences. This paper discusses the treatment, distribution and evaluation of tablets since the first major discoveries in 1850, the problems and potential advantages of identifying clay sources and methods of manufacture, the challenges of preserving and recording tablets found in different conditions in the field, and the development of cleaning and long-term conservation techniques. Early experiments in firing tablets at the British Museum and at Babylon were followed by the systematic work of Friedrich Rathgen in Berlin around 1900. While his methods were gradually accepted in principle, there was limited communication among specialists, and independent procedures evolved. The debate on best practice continues.