CUERDA SECA — meaning 'dry cord' in Spanish, is a decorative technique employed in tiling. The process begins by outlining the design using a mixture of iron or manganese oxide and grease. Subsequently, colours are applied, but they are carefully prevented from crossing the greasy lines. After firing, the outlines appear as sunken, matte dark lines that demarcate areas of glossy colour.

The earliest incarnation of this technique involved using a thin cord soaked in the iron/manganese and grease mixture, which was meticulously placed on the tile's surface to establish the design's outlines.