Cuerda seca (Spanish for "dry cord") is a technique used when applying coloured glazes to ceramic surfaces.

When different coloured glazes are applied to a ceramic surface, the glazes have a tendency to run together during the firing process. In the cuerda seca technique, the water-soluble glazes are separated on the surface by thin lines of a greasy substance to prevent them running out of their delineated areas. A dark pigment such as manganese carbonate is usually mixed with the grease to produce a dark line around each coloured area.^[1]

Although some scholars have postulated a Timurid-Iranian origin,^[2] many scholars believe that the cuerda seca technique originated primarily in al-Andalus (Islamic Spain and Portugal) in the second half of the 10th century, during the Umayyad period (citing Umayyad-era examples from Suza).^[3][4][5][6] The technique was further advanced during the Taifas period in the 11th century.^[4] Preserved fragments of tiles from the late 12th-century minaret of the Kasbah Mosque in Marrakesh, Morocco, have been cited as the earliest surviving example of cuerda seca tilework being used for architectural decoration.^[6]

In central Asia tiles were manufactured using the cuerda seca technique from the second half of the 14th century.^[7] The introduction of different coloured glazes is recorded in the mausoleums of the Shah-i-Zinda necropolis in Samarkand. In the 1360s the colours were restricted to white, turquoise and cobalt blue but by 1386 the palette had been expanded to include yellow, light-green and unglazed red.^[8] Large quantities of cuerda seca tiles were produced during the Timurid (1370–1507) and Safavid (1501–1736) periods.^[9]

In the 15th century Persian potters from Tabriz introduced the technique into Turkey and were responsible for decorating the Yeşil Mosque in Bursa (1419-1424).^[10] Within the Ottoman Empire cuerda seca tilework fell out of fashion in the 1550s and new imperial buildings were decorated with underglaze-painted tiles from İznik. The last building in Istanbul to include cuerda seca tilework was the Kara Ahmed Pasha Mosque which was designed in 1555 but only completed in 1572.^[11][12]

• Pitcher in cuerda seca style from Susa in Iran, 8th-9th century
• Cuerda seca tile from the Alcazar of Seville, 12th-13th century
• Tiles in the Green Mosque, Bursa, c. 1420
• Details of the Green Tomb in Bursa
• Tile from Khargird in Iran, mid 15th century
• Ottoman tile, Istanbul, first half 16th century
• Dish from Seville in Spain, early 16th century