What type of artwork fills the windows of Gothic cathedrals?

What type of artwork fills the windows of Gothic cathedrals? Stained glass fills many of them.

Stained glass is made from pieces of coloured or painted glass arranged into pictorial and geometric designs, traditionally held together by lead strips and supported by metal frames. In Gothic churches, these windows transformed walls into luminous storytelling surfaces, often showing biblical scenes, saints, rulers, or the trades that helped fund the work.

The style expanded alongside Gothic engineering. Pointed arches, rib vaults, and flying buttresses shifted much of the building’s weight away from the walls, allowing windows to become larger. Abbot Suger’s rebuilding of the Basilica of Saint-Denis in the 12th century helped establish the idea that coloured light could convey divine splendour.

The answer does not mean every Gothic window is stained glass; some contain clear or grisaille glass, stone tracery, or later replacements. “Tapestry,” “mosaic,” and “fresco” are different media: tapestry is woven, mosaic uses small pieces of material, and fresco is painted onto wet plaster.