When did the Roman's make their pottery?

This site will give you some background in Roman Pottery, an excerpt:

The Romans followed the Greeks and Etruscans in making their better pottery from a fine red terracotta body. Red clays are the most common clays in central Italy, and the Romans were traditionalists. They also adopted the Greek technique of using a smooth iron rich slip glaze to coat a coarser body. But, unlike the Greeks, the Romans usually preferred the simpler clear oxydised firing. In this firing the iron slip produced a glossy RED finish rather than a glossy BLACK.

* http://www.ceramicstudies.me.uk/histx108.html