Two aspects of Muslim culture led to the elevation of calligraphy to an important art form in Islam. The first was the profound reverence placed on the word of God as transcribed by the hand of his prophet, Muhammad, in the Muslim holy text, the Qur'an. The second was the fact that figural depiction in art was proscribed by orthodox Islamic law, which led artists to explore non-figural designs, such as geometric patterns, floral motifs and calligraphy (see more on this in the Islam section of the exhibition).

Quotations from the Qur'an and other Islamic sources were commonly used as decoration for both religious and secular building facades. The most efficient method (as well as the most durable) was to write with brush on tiles, which were then fired to make the writing indelible. In examples such as these two from the Victoria and Albert Museum, the calligraphic script was carved in clay, creating a mold from which multiple, identical tiles could be mass-produced. The glazing method used here is a technique, by which a lustrous glaze suffused with metallic particles is applied to give the surface a rich, glimmering sheen. The earliest examples of this technique date to ninth century Iraq and Egypt.¹

It was not unusual for craftsmen to identify themselves and their patrons on Timurid architectural projects; these tiles are signed by Nusratuddin Muhammad, commissioned for Abu-Sa'id (d. 1469).²  Although not known for his patronage of architecture, a number of buildings were erected either by Abu-Sa'id or by family members in both Samarkand and Herat.³  These tiles may have originally been incorporated into any of these projects, though the flower-and-vase motif recalls designs used in earlier Timurid architecture, such as Shah-i Zinde.⁴

References:

(1) Thomas W. Lentz and Glenn D. Lowry, Timur and the Princely Vision: Persian Art and Culture in the Fifteenth Century (Los Angeles: Los Angeles County Museum of Art, 1989), p. 352.

(2) Ibid.

(3) Bernard O'Kane, Timurid Architecture in Khurasan (Costa Mesa, CA: Mazda Publishers, 1987), pp. 251-53.

(4) Lentz and Lowry, ibid.