thick paint. (The suggestion that a hollow needle could account for such features seems somewhat unlikely.) The application of relief outlines was necessary, as the rather liquid glossy clay would otherwise have turned out too dull. After the technique's initial phase of development, both alternatives were used, to differentiate gradations and details more clearly. The space between figures was filled with a glossy grey clay slip. Then, the vases underwent triple-phase firing, during which the glossy clay reached its characteristic black or black-brown color through reduction, the reddish color by a final re-oxidation. Since this final oxidizing phase was fired using lower temperatures, the glazed parts of the vase did not re-oxidize from black to red: their finer surface was melted (sintered) in the reducing phase, and now protected from oxygen. The new technique had the primary advantage of permitting a far better execution of internal detail. In black-figure vase painting such details had to be scratched into the painted surfaces, which was always less accurate than the direct application of detail with a brush. Red-figure depictions were generally more lively and realistic than the black-figure silhouettes. They were also more clearly contrasted against the black backgrounds. It was now possible to depict humans not only in profile, but also in frontal, rear, or three-quarter perspectives. The red-figure technique also permitted the indication of a third dimension on the figures. However, it also had disadvantages. For example, the distinction of sex by using black slip for male skin and white paint for female skin was now impossible. The ongoing trend to depict heroes and deities naked and of youthful age also made it harder to distinguish the sexes through garments or hairstyles. In the initial phases, there were also miscalculations regarding the thickness of human figures. In black-figure vase painting, the pre-drawn outlines were a part of the figure. In red-figure vases, the outline would, after firing, form part of the black background. This led to vases with very thin figures early on. A further problem was that the black background did not permit the depiction of space in any depth, so that spatial perspective was almost never attempted. Nonetheless, the advantages outnumbered the disadvantages. The depiction of muscles and other anatomical details clearly illustrates the development of the style. Attica Black-figure vase painting had been developed in Corinth in the 7th century BCE and quickly became the dominant style