According to modern research, the workshops were owned by the potters. The names of about 40 Attic vase painters are known, from vase inscriptions, usually accompanied by the words (égrapsen, has painted). In contrast, the signature of the potter, (epoíesen, has made) has survived on more than twice as many, namely about 100, pots (both numbers refer to the totality of Attic figural vase painting). Although signatures had been known since c. 580 BCE (first known signature by the potter Sophilos), their use increased to an apex around the Pioneering Phase. A changing, apparently increasingly negative, attitude to artisans led to a reduction of signatures, starting during the Classical period at the latest. Overall, signatures are quite rare. The fact that they are mostly found on especially good pieces indicates that they expressed the pride of potter and/or painter. The status of painters in relation to that of potters remains somewhat unclear. The fact that, e.g., Euphronius was able to work as both painter and potter suggests that at least some of the painters were not slaves. On the other hand, some of the known names indicate that there were at least some former slaves and some perioikoi among the painters. Additionally, some of the names are not unique: for example, several painters signed as Polygnotos. This may represent attempts to profit from the name of that great painter. The same may be the case where painters bear otherwise famous names, like Aristophanes (vase painter). The careers of some vase painters are quite well known. Apart from painters with relatively short periods of activity (one or two decades), some can be traced for much longer. Examples include Douris, Makron, Hermonax and the Achilles Painter. The fact that several painters later became potters, and the relatively frequent cases where it is unclear whether some potters were also painters or vice versa, suggest a career structure, perhaps starting with an apprenticeship involving mainly painting, and leading up to being a potter. This division of labor appears to have developed along with the introduction of red-figure painting, since many potter-painters are known from the black-figure period (including Exekias, Nearchos and perhaps the Amasis Painter). The increased demand for exports would have led to new structures of production, encouraging specialisation and division of labor, leading to a sometimes ambiguous distinction between painter and potter. As mentioned above, the painting of vessels was probably mainly