'stamped bronze') consisted of cast ingots of bronze of measured quality and weight, embossed with a government stamp, used as currency in Rome and central Italy starting in the 5th century BC before the introduction of aes grave in the mid 3rd century BC.
Popular tradition ascribes them to Servius Tullius, but due to the high quality of art found on even the earliest specimens, this seems very unlikely.
[2] The earliest aes signatum was not cast in Rome proper, but in central Italy, Etruria, Umbria, and Reggio Emilia.
The same fragmentation into smaller change applies to later aes signatum issued by the city of Rome, which did correspond to the Roman heavy standard for the as.
The Roman aes signatum conforms more strictly to size and weight standards because they are an official issue, where the ramo secco bars were more of a recognizable item of barter exchange that would be weighed, rather than taken at a face value.