Red figure is, put simply, the reverse of the black figure technique. Both were achieved by using the three-phase firing technique. The paintings were applied to the shaped but unfired vessels after they had dried to a leathery, near-brittle texture. In Attica, the normal unburnt clay was of orange colour at this stage. The outlines of the intended figures were drawn either with a blunt scraper, leaving a slight groove, or with charcoal, which would disappear entirely during firing. Then the contours were redrawn with a brush, using a glossy clay slip. Occasionally, the painter decided to somewhat change the figurative scene. In such cases the grooves from the original sketch sometimes remain visible. Important contours were often drawn with a thicker slip, leading to a slightly protruding outline (relief line); less important lines and internal details were drawn with diluted glossy clay.