How do oil paint, tempera, fresco, watercolor, and acrylic paint differ?

In Western painting, these mediums differ primarily in their binding agents, application methods, and physical properties:

• Oil painting: Pigments are suspended in drying oils, such as linseed oil. It is prized for its versatility, allowing for smooth blending, textural depth, and both opaque and transparent layers. It dries slowly, enabling artists to work over long periods.1
• Tempera painting: Pigments are mixed with a water-miscible binder, traditionally egg yolk. It dries quickly to form a durable, matte, and opaque film, often requiring a crosshatching technique for modeling because it does not blend as easily as oil.2
• Fresco painting: This involves applying water-based pigments directly onto plaster. In buon fresco, the pigment becomes an integral part of the wall as it dries. Fresco secco is applied to dry, limewater-soaked walls, forming a surface film.34
• Watercolour: Pigments are ground in a water-soluble gum (usually gum arabic) and applied to paper. It is defined by its transparency; artists build images by layering washes, using the white of the paper to create highlights.5
• Acrylic paint: A synthetic resin emulsion that thins with water. It combines the expressive range of oils with the rapid drying time of tempera, forming a durable, waterproof, and flexible film.6