Thermoluminescence dating, photographic documentation and methods of material science were used to evaluate a terracotta plaque attributed to Ghiberti for the Moses Panel of the Bapistry Doors, Florence. Evidence gathered by these means suggests that Ghiberti's workshop did make the terracotta plaque as a working model for one panel of the Bapistry doors. The thermoluminescence date shows that the plaque was made in the Renaissance. Emission spectroscopy and the SEM were used to identify the composition of the plaque as an illitic clay. Refiring tests indicate a low firing temperature for the piece. Macro and microstructure of the plaque were also studied to determine the sequence and methods of manufacture and restoration.