Thuluth
The Thuluth script ( Persian ثلت Sols ; Arabic ثلث, DMG ṯuluṯ 'third', Ottoman ثلت Sülüs ) belongs to Ibn Muqla's canon of the six italic writing styles ( al-aqlam as-sitta ) of Arabic calligraphy . It is characterized by the particular flexibility of the letters with large ascenders and sweeping endings and is often found as decorative font on mosques and other buildings. Thuluth became particularly popular in the Ottoman Empire .
The calligrapher Ali Naghi Emami , his son Mohammad Mohsen Emami and in turn his son Mohammad Reza Emami were famous for their Thuluth works in the Safavid era. The various inscriptions on the historical buildings in Isfahan , Meshhed , Qom and Casvin were created by them.