Ionic order cap is usually enriched with egg-and-dart. Since Vitruvius, a female character has been ascribed to the Ionic (in contrast to the masculine Doric). The major features of the Ionic order are the volutes of its capital, which have been the subject of much theoretical and practical discourse, based on a brief and obscure passage in Vitruvius. The only tools required to design these features were a straight-edge, a right angle, string (to establish half-lengths) and a compass. Below the volutes, the Ionic column may have a wide collar or banding separating the capital from the fluted shaft (as in, for
Giacomo Barozzi da Vignola company with Baldassare Peruzzi, Giulio Romano, Andrea Palladio and others furnished material for an exhibition in 2001 His two published books helped formulate the canon of classical architectural style. The earliest, "Regola delli cinque ordini d'architettura" ["Canon of the five orders of architecture"] (first published in 1562, probably in Rome), presented Vignola's practical system for constructing columns in the five classical orders (Tuscan, Doric, Ionic, Corinthian and Composite) utilising proportions which Vignola derived from his own measurements of classical Roman monuments. The clarity and ease of use of Vignola's treatise caused it to become in succeeding centuries the most published