Scanning electron microscopy, electron microprobe analysis and x-ray diffraction are used to examine the surface finishes of Attic and Samian wares. The use of a single firing cycle to produce both the black and intentional red gloss on Attic ware is confirmed and the processes involved in achieving the differential oxidation of the intentional red gloss plus the body, as compared with the black gloss, are elucidated. The red gloss on Samian ware is shown to be more similar in texture to the black gloss on Attic ware than to the intentional red gloss. -- AATA