Which painting technique involves watercolor painting on wet lime plaster integrated into a building?

• A. Gesso
• B. Horizon line
• C. Fresco
• D. Impasto

Answer: (C)

Fresco is a painting method where pigments, usually water-based, are applied to fresh, damp lime plaster on a wall. As the plaster dries, the pigment fuses with it, so the image becomes an integral part of the building’s surface. This approach is what makes fresco distinct from other wall paintings because the artwork literally becomes part of the masonry as it cures. In buon fresco, the pigment bonds with the wet plaster; when plaster dries, the image is permanently set into the wall. By contrast, fresco secco involves adding pigment to dry plaster, which doesn’t have the same seamless integration. Other options don’t fit this description: gesso is a white ground used on panels, not wall plaster; a horizon line is a drawing element, not a painting technique; impasto is about thickly applied paint to create texture, not about integrating with wall plaster.