The law prescribed with care the dress of Roman prostitutes, on the principle that they were to be distinguished in all things from honest women. Thus they were not allowed to wear the chaste _stola_ which concealed the form, or the _vitta_ or fillet with which Roman ladies bound their hair, or to wear shoes (_soccus_), or jewels, or purple robes. These were the insignia of virtue. Prostitutes wore the _toga_ like men; their hair, dyed yellow or red, or filled with golden spangles, was dressed in some Asiatic fashion. They wore sandals with gilt thongs tying over the instep, and their dress was directed to be of flowered material. In practice, however, these rules were not strictly observed. Courtesans wore jewels and purple robes,[118] and not a few boldly concealed their profligacy under the _stola_. Others, seeking rather to avoid than to court misapprehension as to their calling, wore the green toga proudly, and over it the sort of jacket called _amiculum_, which, like the white sheet of baronial times, was the badge of adultery. Others, again, preferred the silk and gauze dresses of the East (_sericæ vestes_), which, according to the expression of a classical writer, "seemed invented to exhibit more conspicuously what they were intended to hide."[119] Robes of Tyre were likewise in use, whose texture may be inferred from the name of "textile vapor" (_ventus textilis_) which they received. The law strictly prohibited the use of vehicles of any kind to courtesans. This also was frequently infringed. Under several emperors prostitutes were seen in open litters in the most public parts of Rome, and others in litters which closed with curtains, and served the purpose of a bed-chamber.[120] A law of Domitian imposed heavy penalties on a courtesan who was seen in a litter. In the lupanar, of course, rules regarding costume were unheeded. Prostitutes retained their hair black, but as to the rest of their person they were governed by their own taste. Nudity appears to have been quite common, if not the rule. Petronius describes his hero walking in the street, and seeing from thence naked prostitutes at the doors of the lupanaria.[121] Some covered their busts with golden stuffs, others veiled their faces.