Sentence:  Through color and tone Byzantine potters gave to <WSD>sgraffito</WSD> pottery qualities that go beyond the contrasts possible in metalwork. And the history of the colors in their use on Byzantine <WSD>sgraffito</WSD> ware again takes us back to Tang China. 
Meaning of the word marked with <WSD> tags:  A technique in ceramics, art and wall design, where the top layer of pigment or slip is scratched through to reveal an underlying layer.