Final answer:
In oil painting, pigment is suspended in a binder of oil, creating an opaque film as it dries. Oil paint allows for a wide variety of textures and layering, with the potential drawback of cracks forming in thicker layers over time.
Step-by-step explanation:
In oil paint, the suspension of the pigment in oil does indeed create an opaque film as the oil dries. This is because oil paint uses pigment mixed with a binder, usually linseed oil, that serves as a film-forming component which solidifies upon drying. As the oil dries, the pigment is fixed in place, resulting in the beautifully textured and luminous surface characteristic of oil paintings. The process allows for a diverse range of applications, from thin, almost transparent glazes to thick layers known as impasto. However, when impasto is used, the paint may eventually crack along the thickest parts.
During the Renaissance, the luminosity and plasticity of oil paint were highly valued by artists who could slowly build up layers to achieve subtle color gradations and depth. This slow-drying medium meant that colors could be meticulously blended on the painting surface, leading to the realistic and vivid images that are celebrated in oil paintings. Furthermore, the addition of substances like ground glass by some painters enhanced the reflective quality of the paint, adding even more depth and luminosity.