From Glass from Islamic Lands on the Metropolitan Museum of Art website:
In the field of Islamic art, glass is a craft that often rose to excellence but has been largely overlooked by art historians. Thousands of anonymous glassmakers, from Cairo to Delhi, proudly transmitted their knowledge from one generation to the next, experimenting with the colors, shapes, techniques, and surface decoration of this extraordinarily versatile material. Their most outstanding results, from public and private collections worldwide, encourage a widespread appreciation of the artistic forms of Islamic glass—a fitting legacy for this ancient craft.
